Journal of Accounting Research Vol. 40 No. 3 June 2002 Printed in U.S.A. Earnings Predictability, Information Asymmetry, and Market Liquidity J O H N A F F L E C K - G R A V E S ,∗ C A R O L Y N M . C A L L A H A N ,† A N D N I R A N J A N C H I P A L K A T T I‡ Received 1 May 1996; accepted 21 December 2001 ABSTRACT We investigate the relation between earnings predictability, information asymmetry and the behavior of the adverse selection cost component of the bid-ask spread around quarterly earnings announcements for NASDAQ firms. While we find an increase in the adverse selection component of the bid-ask spread on the day of and the day prior to quarterly earnings announcements for firms with less predictable earnings, we find no evidence of such changes for firms with more predictable earnings. During a non-announcement period, we find that firms with relatively less predictable earnings have consistently higher total bid-ask spreads than firms with more predictable earnings. This finding suggests that firms with relatively less predictable earnings have a higher cost of equity capital than comparable firms with more predictable earning streams, ceteris paribus. Hence, earnings predictability may be a legitimate concern of managers who wish to minimize their cost of equity capital at least as it pertains to bid-ask spreads. ∗ University of Notre Dame; †University of Arkansas; ‡Ohio Northern University. We thank I/B/E/S Inc. for their database of earnings estimates and two anonymous referees for their many useful comments and suggestions. We gratefully acknowledge the comments of Linda Bamber, Mary Barth, George Benston, Bill Cready, John Elliott, E. Ann Gabriel, Charles M. C. Lee, Choa-Shin Liu, Mort Pincus, Chris Olsen, Grace Pownall, Tom Stober, Greg Waymire, Ro Verrecchia, and Jerry Zimmerman as well as workshop participants at University of Notre Dame, Case Western Reserve University, Emory University, Michigan State University, The Ohio State University, University of Wisconsin, and Texas A & M University. We are also grateful to workshop participants at the 1996 National American Accounting Association Annual Meeting in Chicago and the 1997 Financial Management Association Meeting in New Orleans. The research support received by Carolyn M. Callahan from the KPMG Foundation is gratefully acknowledged. 561 C , University of Chicago on behalf of the Institute of Professional Accounting, 2002 Copyright 562 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI 1. Introduction We examine the relation between earnings predictability and information asymmetry, as revealed by the change in the adverse selection cost component (hereafter, adverse selection cost) of the bid-ask spread around quarterly earnings announcements while controlling for volume effects. Second, during a non-announcement period, we examine the link between earnings predictability and total bid-ask spreads arguing that higher spreads imply a higher cost of equity capital for the firm, ceteris paribus. The prior empirical evidence on bid-ask spread changes around earnings announcements is mixed. Morse and Ushman [1983] and Skinner [1991], using Over-theCounter (OTC) samples, find no clear evidence of such changes, while Krinsky and Lee [1996] and Lee, Mucklow, and Ready [1993], using New York Stock Exchange (NYSE) samples, find a significant increase in spreads surrounding earnings announcements.1 We extend these earlier studies in two ways. First, unlike Krinsky and Lee [1996] and Lee, Mucklow, and Ready [1993] who focus on NYSE firms, our study examines the bid-ask spreads of 247 National Association of Securities Dealers Automated Quotations (NASDAQ) firms from 1985–90. Examining earnings announcement effects and the cost of transacting using NASDAQ stock market data is of interest because of differences in the accuracy with which transaction costs can be measured on NASDAQ versus NYSE. Also, the inside quotes on NASDAQ are likely to be a better proxy for the actual cost of transacting as NASDAQ market-makers do not face competition from floor traders (Eleswarapu [1997]). Further, the NYSE quoted spreads are only representative in nature, with many of the transactions actually occurring inside the quotes.2 Second, using an ex-ante adverse selection cost model, we examine the impact of earnings predictability, which we operationalize using metrics based on analysts’ annual forecast errors and dispersion. Consistent with the theoretical work in the literature (e.g., Glosten and Harris [1988]), we argue that less predictable earnings releases increase the information asymmetry between privately informed investors and dealers (hereafter, market-makers) in the capital markets. To compensate for this informational disadvantage, we hypothesize that a market-maker’s increase in the bid-ask spread at the time of an earnings announcement will be more pronounced for firms with less predictable earnings. Our empirical results show an increase in the adverse selection cost of the bid-ask spread on the day of and the day prior to quarterly earnings announcement dates for NASDAQ firms with less predictable earnings. In 1 For a survey of the research on the relation between accounting information and bid-ask spreads, see Callahan, Lee, and Yohn [1997]. 2 Huang and Stoll [1996] provide a detailed discussion of structural differences between NASDAQ and the NYSE. They also document significantly more trades inside the quotes for NYSE stocks. EARNINGS PREDICTABILITY 563 contrast, we find no evidence of a significant change in the adverse selection cost of the bid-ask spread around quarterly earnings announcements of firms with highly predictable earnings. Further, we control for the joint effects of volume and spread. We show that our spread results for low predictability firms are not driven by volume decreases. To investigate the broader cost of equity capital implications of our hypothesis, we examine also whether firms with more predictable earnings have lower total bid-ask spreads in a non-announcement period. Our results show that firms with relatively less predictable earnings have consistently higher total bid-ask spreads in the non-announcement period, suggesting that a firm with relatively less predictable earnings will have a higher cost of equity capital than a comparable firm with a more predictable earning stream. 2. Research Hypotheses The extant market microstructure literature demonstrates that the quoted bid-ask spread is a function of three cost components incurred by the marketmaker: order processing, inventory holding, and adverse selection costs. The inventory holding cost represents the market-maker’s cost of holding suboptimal levels of inventories while order processing costs represent the market-maker’s fixed costs such as clearing and settlement costs. The “adverse selection” cost of the spread is directly related to the perceived level of information asymmetry in the capital market as an uninformed marketmaker will increase the spread to compensate for expected losses to privately informed traders (Glosten and Harris [1988]). Prior literature demonstrates that earnings predictability can affect the market response to an earnings release (Imhoff and Lobo [1992] and Pincus [1983]). We argue that firms with less predictable earnings are characterized by relatively larger mean absolute annual forecast errors and larger mean dispersions averaged over several years. Further, we contend that low earnings predictability increases information asymmetry in the market and increases trading opportunities for the informed trader which may influence the market-maker’s adverse selection cost. This argument suggests the following hypothesis: H1: There will be a significant increase in the abnormal adverse selection cost of the bid-ask spread around quarterly earnings announcements for firms with low earnings predictability. Further, we hypothesize that firms with more predictable earnings may also have lower bid-ask spreads in non-announcement periods and hence a lower cost of equity capital: H2: Firms with relatively more predictable earnings have consistently lower total bid-ask spreads across time than firms with less predictable earnings. 564 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI 3. Sample Selection and Variables We draw our sample from the CRSP-NASDAQ 1989 data tapes from the University of Chicago. We restrict the initial sample to NASDAQ firms that are on both the COMPUSTAT tapes (to be used for quarterly and annual financial data) and the Institutional Brokers’ Estimation System (I/B/E/S) consensus tapes (to be used for earnings predictability data). The full analysis period is 1985–90, but the sample includes only firms with full financial data for the years 1980 to 1989 to obtain companies that have been active for at least ten years. We also require that all sample firms file 10-K reports with the Securities Exchange Commission (SEC) on a regular basis because we use these filing dates to select analyst earnings forecasts to calculate our earnings predictability measures. To ensure comparability of our firms, we limit our sample to firms with a December 31 fiscal year-end. Our sample firms must also have annual and quarterly earnings forecast data on the I/B/E/S tape for at least four of the six years from 1984 to 1989, and they must have at least one quarterly earnings announcement published in the Wall Street Journal (WSJ) during the analysis period. We use the annual forecast data to compute the earnings predictability scores while we use the quarterly forecasts to calculate unexpected earnings, a control variable in our robustness tests. Initially, we obtained a sample of 329 firms.3 Fifty-eight of those sample firms did not meet our SEC filing criteria. We excluded twenty firms due to confounding events (mergers, acquisitions, and dividend announcements) in the confounding window starting two days prior to the announcement and ending two days after the announcement (Krinsky and Lee [1996] and Lee, Mucklow, and Ready [1993]). We eliminated an additional four firms from the final sample because of missing data on the I/B/E/S tape or other sources for the variables needed to calculate the earnings predictability score. These reductions led to a final sample of 247 firms. After excluding 57 observations with a value of zero for primary annual earnings per share (eliminated as a forecast error deflator), we base our tests on 2,941 firmevents (quarterly earnings announcements; with observations per quarter, quarter 1; 779, quarter 2; 788, quarter 3; 877, quarter 4; 497). 4. Research Methods We use a standard event study methodology to examine our first hypothesis. Denoting the quarterly earnings announcement date as trading day 0, we set the parameter estimation period to begin 146 trading days (day −146) and to end 11 trading days (day −11) prior to the quarterly earnings announcement date. The analysis period ranges from trading day −3 to trading 3 The update code on COMPUSTAT indicates that the company has been updated from its final source (usually the 10-K or 10-Q). We used this screen to avoid companies with unreliable sources of financial data. EARNINGS PREDICTABILITY 565 day +3, inclusive of trading day 0. In robustness tests, we use a multivariate linear regression model to control for other factors related to the market impact of an earnings announcement such as firm size, reporting lag, number of market-makers, the earnings surprise, and unexpected volume and return. To examine our second hypothesis, we estimate a time series linear regression model to test the prediction that the magnitude of the total bidask spread is decreasing in earnings predictability over a non-announcement period, 9/1/88 to 12/31/90 excluding earnings announcement dates or 589 trading days. 4.1 EARNINGS PREDICTABILITY We use both consensus analysts’ forecast errors and the dispersion of forecasts to measure earnings predictability. The consensus analysts’ forecast for a firm i in year y (CYFi,y , y = 1984 to 1989) is the first consensus annual forecast dated after the year y −1 10-K filing date (Stice [1991]).4 We obtained the primary annual earnings per share before discontinued operations, extraordinary items and cumulative effects of an accounting change (COMPUSTAT annual item #58) (AEPSi,y ) for each firm i for the years y = 1984 to 1989.5 We then calculated the standardized absolute forecast error (SAFEi,y ) as follows: SAFEi,y = |(CYFi,y − AEPSi,y )/AEPSi,y |, (1) Following Imhoff [1992], we calculated the mean standardized absolute forecast error over the period 1984 to 1989 for each firm as follows: SAFEi = 1/K k SAFEi,y (2) y =1 where, K takes the value 4 to 6, depending on data availability. We argue that the higher the mean standardized absolute forecast error, the lower the predictability of the firm’s earnings. Second, for each firm i and each year y, we calculated the relative dispersion of analysts’ forecasts for the first consensus annual forecast issued after the year y −1 10-K report filing date using the standard deviation of analysts’ forecasts as reported by I/B/E/S: DAFi,y = (Standard Deviation of Analysts’ Forecasti,y )/|CYFi,y |. (3) 4 For firms where the SEC date stamp was not clear or was not found on the 10-K report, we used the May consensus forecast to derive the earnings predictability score. This usage is consistent with Swaminathan [1991]. 5 When AEPS , the deflator, is zero, the forecast error measure is undefined, accordingly we i,y excluded 57 zero observations from our sample, less than 2% of the firm observations meeting all other data requirement criteria (Foster [1977] and Sinha, Brown, and Das [1997]). See O’Brien [1988, page 60, footnote 6] for a more detailed discussion of alternative forecast error deflators. 566 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI For each firm i, we calculated the mean relative dispersion of analysts’ forecasts just after the year y −1 10-K report filing date over the period 1984 to 1989 as follows: DAFi = 1/K k DAFi,y . (4) y =1 Once again, K varies from 4 to 6 depending on data availability. We argue that the higher the mean relative dispersion of analysts’ forecasts, the lower the predictability of the firm’s earnings. 4.2 EARNINGS PREDICTABILITY SCORE We compose a firm classification scheme for the earnings predictability scoring that requires benchmark NASDAQ sample medians for SAFE and DAF. To determine the benchmarks for the time period 1984–89, we calculate the mean standardized absolute forecast error (equation 2) and the mean relative dispersion of analysts’ forecasts (equation 4) for all NASDAQ firms with forecast and financial data available on the COMPUSTAT and I/B/E/S tapes with an annual earning announcement date on COMPUSTAT or Dow Jones News Retrieval (DJNR). Our earnings predictability metrics also require a known 10-K SEC filing date. Based on the specified criteria, the NASDAQ sample medians for SAFE and DAF are based on 614 firms and the computed cross-sectional medians are 0.68 and 0.11. We then use these NASDAQ medians to assign an earnings predictability score to each firm event (2,941) in our sample based on the following decision rule: Group Score Decision Rule High Predictability 1 Mixed Predictability 2 Low Predictability 3 SAFEi and DAFi both less than NASDAQ sample medians SAFEi less than NASDAQ sample median but DAFi greater than NASDAQ sample median, or SAFEi greater than NASDAQ sample median but DAFi less than NASDAQ sample median SAFEi and DAFi both greater than NASDAQ sample medians 5. Statistical Models and Tests 5.1 UNIVARIATE TESTS For our univariate event study tests for the abnormal adverse selection cost of the spread and the mean-adjusted abnormal trading volume for the high and low earnings predictability firms in our sample, we use the Brown and Warner [1985] t-Statistic adjusted for autocorrelation (Seyhun [1986, page 195]) based on the following procedures. EARNINGS PREDICTABILITY 567 5.1.1. Abnormal Adverse Selection Cost Measure. To examine the quarterly earnings announcement effect of the adverse selection cost of the bid-ask spread in the analysis period (day −3 to day +3), we define the abnormal adverse selection cost of the spread as the difference between the actual percentage spread (Si,t ) and the expected spread E(Si ) in the absence of informed trading: AAC i,t = Si,t − E (Si,t ) (5) The actual percentage bid-ask spread is defined as: Si,t = ln[ASKi,t − BIDi,t ]/Pi,t (6) where ASKi,t is the ask price for firm i, BIDi,t is the bid price for firm i, and Pi,t is the stock price for firm i defined as the average of the bid and ask prices at the close of trading day t.6 The estimated spread is based on a simultaneous equation model. A system of equations is necessary because of simultaneity between spread and volume (Glosten and Harris [1988] and Hegde and Miller [1989]). In addition, given the presence of non-normalities in the data, we use a log-linear version of the model. We estimate the model based on our 2,941 quarterly earnings announcements (quarter 1; 779, quarter 2; 788, quarter 3; 877, quarter 4; 497) from 1984 to 1989. At each quarterly announcement date, we estimate the following simultaneous equation model separately for each firm observation over the estimation period (day −146 to day −11) using Three Stage Least Squares, assuming cross-correlation between the structural error terms:7 Si,t = a0 + a1 (TV i,t ) + a2 (Pi,t ) + a3 (Ri,t ) + a4 (Si,t−1 ) + ηi,t TVi,t = b 0 + b 1 (Si,t ) + b 2 (MFt ) + b 3 (TVi,t−1 ) + µi,t (7a) (7b) where, (7a) and (7b) are the structural equations; and, TVi,t = the logarithm of the volume of trade for firm event i on trading day t ; Pi,t = the logarithm of the closing price for firm event i on trading day t ; Ri,t = the logarithm of the absolute change in price for firm event i from trading day t − 1 to trading day t ; MFt = the logarithm of the total trading volume on the NASDAQ on trading day t ; t = trading day −146 to trading day −11, the estimation period; 6 Although our focus is on the behavior of the abnormal adverse selection cost of the spread around quarterly earnings releases, we examined also the mean adjusted total spread for comparability with previous studies. Results are available from the authors upon request. 7 If the restrictions imposed in our estimation of equations (7a) and (7b) are in error, parameter estimates arising from Three Stage Least Squares estimation will be inconsistent. To assess the robustness of our estimation results, we reestimated the system using two stage least squares; all results were similar. 568 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI ηi,t = the normally distributed random error term; µi,t = the normally distributed random error term. Pi,t , Ri,t , MFt , Si,t−1 , and TVi,t−1 are exogenous variables, while Si,t and TVi,t are endogenous.8 The first structural equation controls for the inventory and order processing costs of the spread assuming that the abnormal adverse selection cost is orthogonal to these components. The second structural equation accounts for the market-maker’s inventory policy and for possible first-order autocorrelation in volume and spread (Conrad and Niden [1992] and Seyhun [1986]). These exogenous proxy variables are drawn from prior research (Glosten and Harris [1988], Morse and Ushman [1983], and Stoll [1978]). We use Equation (7a) to estimate the expected spread on each trading day in the analysis period (day −3 to day +3) inclusive of the earnings announcement. The estimation equation (7a) is based on the reduced form coefficients from the structural equations and the values of the exogenous variables to obtain the expected spread. The difference between the actual spread on each trading day in the analysis period and the expected spread computed using equation (7a) is an estimate of the abnormal adverse selection cost of the spread. 5.1.2. Brown and Warner [1985] t-Statistic. For tests over the analysis period (day −3 to day +3), the Brown and Warner [1985, page 7] test t -Statistic is used. The t -Statistic is the ratio of the cross-sectional mean abnormal adverse selection cost on event day t to the estimation period time series standard deviation. AACt t-Statistic = (8) sˆAACt where t represents day −146 to day −11, AAC t is the average abnormal adverse selection cost over the 2,941 firm events on day t and ŝ AAC t is the standard deviation of the average abnormal adverse selection cost estimated over the estimation period. By averaging the abnormal adverse selection costs across all observations for an event day, the test statistic adjusts for cross-sectional dependence in firm-specific abnormal adverse selection costs but ignores time series dependence in the same. To correct for the effect of first-order autocorrelation on the mean AAC stream, the test statistic was modified to incorporate the adjustments suggested by Seyhun [1986, page 195]. Empirical examination of the AAC series indicates the process is generated by a first-order autoregressive process of the form: AAC i,t = δ + 1 AAC i,t−1 + µt (9) The standard error of the AAC series is computed by solving the Yule-Walker 8 We reject the null hypothesis that Si,t and TVi,t are exogenous using the Hausman test = 153.74, one-tail p < 0.01). Hence simultaneous equation estimation of spread and volume is appropriate. (χ 2 EARNINGS PREDICTABILITY 569 equations corresponding to equation (9) above.9 The sample standard errors calculated in the estimation period (day −146 to day −11) are multi plied by a factor equal to σ 2 /(1 − φ1 ) where φ is equal to the first order autocorrelation and σ 2 is equal to the random error associated with the first-order autoregression function. 5.2 MULTIVARIATE CONTROL REGRESSION TESTS We use a linear regression model to control for trading lag effects (Hasbrouck [1991]) and other factors related to the impact of the earnings announcement such as firm size, reporting lag, the number of marketmakers, and the earnings surprise. We also control for cross-sectional price and volume effects. With signed predictions of the independent variables indicated, our cross-sectional model estimated over all 2,941 quarterly announcements is defined as follows: + + + + CSUi = α1 + α2 (Q E 2i ) + α3 (Q E 3i ) + α4 (U Ei ) + α5 (L A Gi ) + + ¯ i ) + α8 (CAR i ) + α9 (C VOLi ) + τi (10) + α6 ( M̄ Mi ) + α7 (SI ZE The dependent variable, CSUi is the abnormal adverse selection cost estimates cumulated over the two-day event window (day −1 to day 0) as follows: 0 CSUi = P̄ i AAC i,t (11) t=−1 where AACi,t is defined in equation (5) and P̄ i is the average of the mean bid price and the mean ask price of firm i event in the estimation period (day −146 to day −11). The independent variables are as follow: QE2i = an indicator variable set to 1 if the firm observation is in the medium earnings predictability group (i.e., with score 2) and 0 otherwise; QE3i = an indicator variable set to 1 if the firm observation is in the low earnings predictability group (i.e., with score 3) and 0 otherwise; UEi = the logarithm of the unexpected quarterly earnings of the firm in that quarter; LAGi = an indicator variable set to 1 if the firm reports later than the expected lag period and 0 otherwise; MMi = the logarithm of the average number of market-makers dealing in the security in the estimation period; SIZEi = the logarithm of the firm’s total assets measured at the beginning of the calendar year prior to the analysis period; 9 The first order serial correlation was determined by examining the partial autocorrelation coefficients (PACF) of AACt in equation (9) at lag (1). The PACF is 0.27 with t-statistic = 8.89 and p = 0.00 for the high earnings predictability group, N = 850, and 0.15 with t-statistic = 2.45 and p = 0.01 for the low earnings predictability group, N = 1, 124. For a discussion of autoregressive processes and diagnostic tests, see Box and Jenkins [1976]. 570 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI CARi = the risk adjusted two-day cumulative abnormal return over the event period (day −1 to day 0); CVOLi = the mean adjusted cumulative abnormal volume over the event period (day −1 to day 0); τi = the normally distributed random error term. We examine the robustness of the earnings predictability effect using two indicator variables QE2i and QE3i . Our hypothesis that the cumulative adverse selection cost is expected to be greater for firms with low earnings predictability predicts that α3 > α2 > α1 . We compute unexpected earnings UEi as the logarithm of the absolute value of the difference between the reported primary quarterly earnings per share (COMPUSTAT quarterly item #19) and the last I/B/E/S consensus analyst forecast of the firm’s primary earnings per share for the quarter issued prior to the earnings announcement date. α4 is predicted to be positive as the larger the magnitude of the unexpected earnings component, the greater the value of the informed traders’ unique firm information which increases the adverse selection cost faced by the marketmakers. The timeliness of the release of the earnings report can effect the adverse selection cost of the market-maker as the longer the earnings announcement is delayed, the larger the window available to informed traders to trade on their unique information. We define the actual reporting lag as the calendar time from the end of the quarterly fiscal period up to and including the announcement date (Chambers and Penman [1984]). The actual reporting lag in the previous fiscal period is used as the expected lag in the analysis period. α5 is predicted to be positive as it reflects the unanticipated delay in the release of the earnings report. As the number of market-makers making a market in a stock increases, the more liquid will be the market for the security (Copeland and Galai [1983]). We obtain the number of market-makers for each trading day in the estimation period (day −146 to day −11) from the CRSP-NASDAQ tape and the average over the 136 trading days in the estimation period provides the estimate for each firm event. We expect that α6 will be negative as an increase in the number of market-makers reduces the adverse selection cost faced by each market-maker individually. Atiase [1987] provides empirical evidence that the pre-disclosure information available for a firm varies positively with the firm’s size. Therefore, α7 is predicted to be negative as small firms with lower levels of pre-disclosure information are more likely to provide opportunities for informed trading against the market-maker and thereby increase adverse selection cost. Lee, Mucklow, and Ready [1993, table 5] report a more pronounced widening of spreads in firms with greater subsequent price movements and show changes in spread around earnings announcements are primarily related to volume. To examine whether our low earnings predictability results are driven by cross-sectional volume and price response to the quarterly EARNINGS PREDICTABILITY 571 earnings announcement, we include the two-day cumulative abnormal return (CAR i ) and abnormal volume (CVOL i ) in our model. To control for price response, CAR i is defined as the risk-adjusted two-day cumulative abnormal return from trading day −1 to trading day 0, where trading day 0 is the quarterly earnings announcement date obtained from the quarterly COMPUSTAT tape or DJNR. Market model parameters necessary to compute CAR i are estimated using daily stock returns and the value-weighted market returns as collected from the CRSP files over the estimation period (day −146 to day −11). To control for volume effects, we include cumulative abnormal volume (CVOL i ) in our model. We define CVOL i as the two-day cumulative mean adjusted abnormal volume from trading day −1 to trading day 0. First we calculate the mean daily percentage of firm i’s shares traded in the estimation period (day −146 to day −11). Abnormal volume is then defined as the difference between the actual percentage of firm i’s shares traded on trading day t and the mean pre-announcement period volume. 5.3 LINEAR REGRESSION TIME SERIES TEST Based on our earnings predictability classification scores (high, medium, and low), three portfolios of firms were formed on each trading day over a non-announcement period, 9/1/88 to 12/31/90 excluding earnings announcement dates, 589 trading days. We then computed the portfolio mean percentage spread (the total bid-ask spread deflated by the average price at the close of trading on day d) for each earning predictability group on each of the 589 trading days in the non-announcement period. To test the prediction that the magnitude of the total bid-ask spread is decreasing in earnings predictability, we use the 1,767 daily earnings predictability group means (3 groupings × 589 trading days) to estimate a time series linear regression model as follows: PSPRDg,d = α1 + α2 (QE2g,d ) + α3 (QE3g,d ) + α4 (Y 90) + τg,d (12) where g is the earnings predictability group (high, medium, low) and d is trading day 1 (9/1/88) through trading day 589 (12/31/90) in the nonannouncement period. Huang and Stoll [1996] document an increase in the level of the bid-ask spread in 1990. Therefore, we use the indicator variable Y90 which is set to 1 if the trading day is in year 1990 and 0 otherwise.10 6. Results Our sample contains 247 companies and 2,941 firm quarter observations.11 Of the 2,941 firm observations, we classify 1,124 in the low earnings 10 Figure 1 also suggests that spreads may be larger in 1990 than in 1988 and 1989. Excluding Y90 does not alter the significance we report for coefficients α2 and α3 in table 4. 11 For most events in our sample (76%), the mean bid-ask spread falls between 1/4 and 3/4. Descriptive statistics (means and standard deviations) for the spread, daily volume, bid and ask price, and firm size for sample firms are also available from the authors. 572 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI TABLE 1 Industry Classification of Sample Observations From 1985 to 1990 a Two-Digit SIC 12 13 20 22 24 25 26 27 28 29 30 32 33 34 35 36 37 38 42 45 48 Industry Coal/lignite mining Mining: non-metallic minerals Food & kindred products Textile mill products Lumber & wood products Furniture & fixtures Paper & allied products Printing and publishing Chemicals & allied products Petroleum refining & related Rubber & misc. plastic products Stone, clay, glass, concrete products Primary metal industry Fabricated metal except machinery Machinery except electrical Electrical, electrical machinery Transportation equipment Instruments and related products Motor freight, transport, etc. Transportation by air Communication No. of Firms Observations Number of Firm Events by Earnings Predictability Groupb Highc Mediumd Low e 5 5 45 55 15 0 0 0 30 55 4 63 0 26 37 2 2 16 43 16 0 0 43 0 0 2 11 5 7 9 106 72 98 0 18 72 86 0 36 0 12 9 52 0 0 3 28 28 0 0 2 23 0 0 23 2 21 0 21 0 2 2 45 11 0 0 0 0 45 11 14 195 0 78 117 13 182 29 84 69 7 72 0 67 5 13 179 43 58 78 6 64 0 18 46 2 11 21 105 0 0 0 72 21 33 predictability group and 850 in the high earnings predictability group. The industry classification of our sample based on two-digit SIC codes is displayed in table 1. One hundred and six firms (42.9% of the sample) are clustered in regulated industries (SICs 49, 60, 63, and 65) and represent 1,193 firm-events. Of these 1,193 firm-events, 451 are classified in the high predictability group, and 385 in the low predictability group.12 12 To ensure that our results were not caused by the special characteristics of regulated firms, we replicated all tests using the subsample excluding these firms. All our inferences were unchanged. EARNINGS PREDICTABILITY 573 T A B L E 1—Continued Two-Digit SIC 49 50 51 54 60 63 65 73 87 Industry Electric, gas, sanitary services Durable goods-wholesale Non-Durable goods-wholesale Retail-Food Stores Banking Insurance Real Estate Business Services Other Totals No. of Firms Observations Number of Firm Events by Earnings Predictability Groupb Highc Mediumd Low e 9 99 49 24 26 6 4 92 60 0 60 0 0 92 0 2 70 11 16 7 2 16 780 147 167 108 19 16 380 22 0 16 0 0 170 45 118 76 19 0 230 80 49 16 0 247 2,941 850 967 1,124 a The sample includes 247 firms and 2,941 firm quarter observations (quarter 1; 779, quarter 2; 788, quarter 3; 877, quarter 4; 497) classified by two-digit SIC code. Each observation is based on a quarterly earnings announcement. b Firms are classified into an earnings predictability group based on both the mean standardized absolute value consensus analysts’ forecast error (SAFE) and dispersion of forecasts (DAF) over the period 1984–89. SAFE is the absolute value of primary annual earnings per share before discontinued operations, extraordinary items and cumulative effects of an accounting change (COMPUSTAT annual item #58) minus the first consensus annual forecast dated after the year y -1 10-K filing date, standardized by primary annual earnings per share defined per the numerator. DAF is dispersion of analysts’ forecasts for the first consensus annual forecast issued after the year y -1 10-K report filing date using the standard deviation of analysts’ forecasts as reported by I/B/E/S, deflated by the absolute value of the first consensus annual forecast dated after the year y -1 10-K filing date. The firm classification scheme for the earnings predictability scoring requires benchmark NASDAQ sample medians for SAFE and DAF. To determine the benchmarks for the time period 1984–89, we calculate the mean standardized absolute forecast error (equation 2 in the text) and the mean relative dispersion of analysts’ forecasts (equation 4 in the text) for all NASDAQ firms with forecast and financial data available on the COMPUSTAT and I/B/E/S tapes with an annual earning announcement date on COMPUSTAT or DJNR (known 10-K filing date). Based on the specified criteria, the NASDAQ sample medians for SAFE and DAF are based on 614 firms and the computed cross-sectional medians are 0.68 and 0.11. We then use these NASDAQ medians to assign an earnings predictability score to each firm event (2,941) in our sample. c Firms classified in the highest predictability group (1) have both the average absolute forecast error and average dispersion over the period 1984–89 less than the respective NASDAQ sample medians for the same metrics. d Firms classified in the medium predictability group (2) have average absolute forecast error less than the NASDAQ sample median for SAFE but average dispersion greater than the NASDAQ sample median for DAF over the period 1984–89 or average absolute forecast error greater than the NASDAQ sample median for SAFE but average dispersion less than the NASDAQ sample median for DAF over the period 1984–89. e Firms classified in the lowest predictability group (3) have both the average absolute forecast error and average dispersion over the period 1984–89 greater than the respective NASDAQ sample medians for the same metrics. In panel A of table 2, we present the frequency and the median of both the standardized absolute forecast error (SAFEi ) and the dispersion of analysts’ forecasts (DAFi ) for each category of earnings predictability based on our sample of 2,941 firm events. To classify the firm events into earnings predictability groups, we estimate also a standardized absolute forecast error and a dispersion of analysts’ forecasts for all firms on NASDAQ with available financial and forecast data (614 firms). Our NASDAQ sample medians are 0.68 and 0.11 for SAFEi and DAFi . Using a Median Chi-Square (KruskalWallis) test, we reject the null hypothesis of equality of the population 574 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI medians across earnings predictability groups for SAFEi and DAFi at twotailed p < 0.01 in both cases. We examine the association between our earnings predictability measures and the number of prior accounting changes and earnings variability. Variability of earnings per share was calculated as the standard deviation of the basic primary earnings per share—excluding extra-ordinary items (COMPUSTAT quarterly item #19) for each available quarter for each firm i for the years y = 1980 to 1989. The number of accounting policy changes for each firm i is the frequency of such changes over the ten year period 1980 to 1989 and was obtained from COMPUSTAT(COMPUSTAT annual footnote file code AC) and verified with the firm’s 10-K report. This investigation follows from Elliott and Philbrick [1990] who document that analysts’ annual earnings forecasts are more dispersed and less accurate in the year of an accounting policy change. Using our classification system, we find that both the mean number of accounting policy changes and the variability of earnings per share are lower for our high earnings predictability firms than for the low predictability firms. An analysis of variance (ANOVA) F -test of mean difference across the three groupings for the number of accounting policy changes and variability of primary earnings per share indicated in panel B of table 2 was significant at the 0.01 and 0.00 level, respectively. In addition, the mean difference t -test comparing firms with high predictability of earnings (group 1) to low predictability firms (group 3) is significant at the 0.01 level for both the accounting policy change variable and the variability of primary earnings per TABLE 2 Classification of Sample Firm Events into Earnings Predictability Groups a Panel A: Grouping Based on Analysts’ Forecast Errors and Dispersion Metrics Earnings Predictability Group Firm Events High: (Score = 1) 850 Medium: (Score = 2) 967 Low: (Score = 3) NASDAQ sample firms 1,124 614 Decision Rule Forecast error and dispersion less than NASDAQ sample medians Forecast error less than NASDAQ sample median but dispersion greater than NASDAQ sample median, or forecast error greater than NASDAQ sample median but dispersion less than NASDAQ sample median Forecast error and dispersion greater than NASDAQ sample median Median Standardized Absolute Forecast Error Dispersion of Analysts’ Forecast Error 0.21 0.03 0.52 0.05 1.14 0.20 0.68 0.11 EARNINGS PREDICTABILITY T A B L E 2—Continued 575 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI 576 TABLE 3 Univariate t-Tests and Regression Results Associated with Differential Adverse Selection Costs Based on Earnings Predictability Groups For 1984 to 1989 Panel A: Behavior of Abnormal Adverse Selection Cost and Trading Volume Around the Quarterly Earnings Announcements (QEA) Segmented by Earnings Predictability (High or Low) Abnormal adverse selection costa Dayc −3 −2 −1 0 1 2 3 Abnormal volumeb High (n = 850) Low (n = 1,124) High (n = 850) Low (n = 1,124) Mean (s.d.)e t-Statisticd 0.028 1.54 (0.018) −0.024 −1.38 (0.018) 0.030 1.64 (0.018) 0.028 1.56 (0.018) −0.025 −1.38 (0.018) −0.018 −0.98 (0.018) 0.016 0.87 (0.018) Mean (s.d.) t-Statistic −0.037 −3.67∗∗ (0.009) 0.019 1.85 (0.009) 0.065 6.42∗∗ (0.009) 0.029 2.87∗∗ (0.009) −0.017 −1.65 (0.009) −0.015 −1.45 (0.009) −0.048 −4.78∗ (0.009) Mean (s.d.) t-Statistic −0.186 −2.71∗∗ (0.069) −0.036 −0.52 (0.069) 0.261 3.81∗∗ (0.069) 0.341 4.97∗∗ (0.069) 0.105 1.53 (0.069) 0.169 2.47∗ (0.069) 0.027 0.40 (0.069) Mean (s.d.) t-Statistic −0.133 −0.96 (0.140) −0.109 −0.78 (0.140) 0.481 3.45∗∗ (0.140) 0.727 5.14∗∗ (0.140) 0.574 4.11∗∗ (0.140) 0.252 1.81 (0.140) 0.184 1.32 (0.140) Panel B: Regression of the Cumulative Adverse Selection Cost of the Spread Surrounding Quarterly Earnings Announcements on Earnings Predictability Indicators and Other Market Related Factors Model: CSUi = α1 + α2 (QE 2)i + α3 (QE 3)i + α4 (UE)i + α5 (LAG)i + α6 (MM)i + α7 (SIZE)i + α8 (CAR)i + α9 (CVOL)i + τi Variablef Expected Sign Estimated Coefficient t-Statistic Intercept QE 2i QE 3i UEi LAGi MMi CARi SIZEi CVOLi − + + + + − + − + −0.025 0.005 0.017 0.300 0.042 0.034 0.000 0.016 0.072 −1.417 1.544 2.657∗ 1.471 0.047 2.367∗ 3.675∗∗ 1.481 3.395∗∗ Number of Observations F -Statistic Prob Value Adjusted R2 2,941 4.643 0.001 0.170 a In panel A, we define the abnormal adverse selection cost of the spread for a firm i as the difference between the actual percentage spread and the expected spread in the absence of informed trading. The actual spread is defined as the logarithm of the difference between the ask price for firm i and the bid price for firm i deflated by the stock price for firm i (defined as the average of the bid and ask prices) at the close of trading day t. The estimated spread is based on a log-linear simultaneous equation model because of simultaneity between spread and volume (Glosten and Harris [1988] and Hegde and Miller [1989]). We estimate the model based on our sample of 2,941 quarterly earnings announcements from 1984–89. At each quarterly announcement date, we estimate equations (7a) and (7b) in the text separately for each firm observation over the estimation period (day −146 to day −11) using Three Stage Least Squares. We use equation (7a) to estimate the expected spread on each trading day in the analysis period (day −3 to day +3) inclusive of the earnings announcement date. The estimation equation (7a) is based on the reduced form coefficients from the structural equations and the values of the exogenous variables to obtain the expected spread. EARNINGS PREDICTABILITY 577 b We calculate the mean daily percentage of firm i’s shares traded in the estimation period (day −146 to day −11). Abnormal volume is then defined as the difference between the actual percentage of shares traded on trading day t and the mean pre-announcement period volume. c This represents the trading day relative to the quarterly earnings announcement. d For the high and low earnings predictability firms in our sample associated with the tests over the analysis period (day −3 to day +3), we use the Brown and Warner [1985, page 7] t-Statistic. The t-Statistic is the ratio of the cross-sectional mean abnormal adverse selection cost on any event day t to the estimation period time series standard deviation. t-Statistic = AAC t sˆ AAC t where t represents trading day −146 to trading day −11, AAC t is the average abnormal adverse selection cost over the 2,941 firm events on trading day t and sˆ AAC t is the standard deviation of the average abnormal adverse selection cost estimated over the estimation period. To correct for the effect of first-order autocorrelation on the mean AAC stream, the Brown and Warner [1985] test statistic was modified to incorporate the autocorrelation adjustments suggested by Seyhun [1986, page 195]. The sample standard errors calculated in the estimation period (day −146 to day −11) are multiplied by a factor equal to σ 2 /(1 − φ1 ) where φ is 2 equal to the first order autocorrelation and σ is equal to the random error associated with the first-order autoregression function. e Standard deviation of the firm events. f Definition of variables: CSUi : the dependent variable, the two-day abnormal adverse selection cost estimates cumulated over the two-day event window (day −1 to day 0) where day 0 is the quarterly earnings announcement date obtained from the quarterly COMPUSTAT tape or DJNR. QE 2i : an indicator variable set to 1 if the firm observation is in the medium earnings predictability group (i.e., with score 2) and 0 otherwise. QE 3i : an indicator variable set to 1 if the firm observation is in the low earnings predictability group (i.e., with score 3) and 0 otherwise. UEi : the logarithm of the absolute value of the difference between the reported primary quarterly earnings per share (COMPUSTAT quarterly item #19) and the last I/B/E/S consensus analyst forecast of the firm’s primary earnings per share for the quarter issued prior to the earnings announcement date. LAGi : an indicator variable set to 1 if the firm reports later than the expected lag period and 0 otherwise. The actual reporting lag is the calendar time from the end of the quarterly fiscal period up to and including the announcement date (Chambers and Penman [1984]). The actual reporting lag in the previous fiscal period is used as the expected lag in the analysis period. MMi : the logarithm of the number of market-makers for each trading day in the estimation period (day −146 to day −11) from the CRSP-NASDAQ tape and the average over the 136 trading days in the estimation period provides the estimate for each firm event. SIZEi : the logarithm of the firm’s total assets measured at the beginning of the calendar year prior to the analysis period. CARi : the risk-adjusted two-day cumulative abnormal return from trading day −1 to trading day 0, where trading day 0 is the quarterly earnings announcement date obtained from the quarterly COMPUSTAT tape or DJNR. Market model parameters necessary to compute CARi are estimated using daily stock returns and the value-weighted market returns as collected from the CRSP files over the estimation period (day −146 to day −11). CVOLi : the two-day cumulative mean adjusted abnormal volume from trading day −1 to trading day 0 where trading day 0 is the quarterly earnings announcement date for firm event i. First we calculate the mean daily percentage of firm i’s shares traded in the estimation period (day −146 to day −11). Abnormal volume is then defined as the difference between the actual percentage of firm i’s shares traded on trading day t and the mean pre-announcement period volume. τi : the normally distributed random error term. ∗ and ∗∗ indicate statistical significance at the 0.05 and 0.01 levels, respectively (two-tailed tests). cost of the spread and the mean-adjusted abnormal trading volume (computed as the logarithm of volume on trading day t during the analysis period (day −3 to day +3) less the mean volume computed over the preannouncement estimation period (day −146 to day −11)) for the high and low earnings predictability firms in our sample.13 13 Given end of the year seasonal return effects, we examine the sensitivity of our findings (inclusive of all four quarterly announcements) to the inclusion of the fourth quarter by examining the behavior of the abnormal adverse selection cost and trading volume around 578 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI Consistent with prior research (e.g., Bamber [1986]), we find a significant positive increase in trading volume around the announcement of quarterly earnings for both the high and low earnings predictability groups. There are, however, no large apparent differences in the abnormal volume we document between the high and low predictability groups during the twoday event window from day −1 to day 0. In the post announcement period, the results indicate that the abnormal increases in the spread are partially reversed on the third day following the earnings release. There is, however, a marked difference between the high and low earnings predictability groups with respect to the abnormal adverse selection cost of the spread. For our sample of 850 high predictability of earnings events, there is no evidence of any significant change in the abnormal adverse selection cost of the spread on the trading day of or the trading day before the earnings announcement. However, the results associated with the 1,124 events for firms with low predictability of earnings are strikingly different. The abnormal adverse selection cost of the spread is significantly increased (at the 0.01 level) on both the day before and the day of the announcement.14 These Brown and Warner [1985] t-tests adjusted for autocorrelation results provide support for our hypothesis that low predictability of earnings firms have spreads with a higher abnormal adverse selection cost at the time of the quarterly earnings releases. The increase in the spread we observe suggests that the increase in volume is not sufficient to offset the increase in the abnormal adverse selection cost. This conclusion is consistent with our hypothesis that lower earnings predictability increases the information asymmetry between investors and traders in the capital markets. We examine the robustness of our conclusion by using a cumulative adverse selection cost metric in the event period from trading day −1 to trading day 0. This cumulative analysis allows us to control for other factors such as firm size, reporting lag, number of market-makers, the earnings surprise, the fourth quarter earnings announcements segmented by earnings predictability (155 high earnings predictability firm events and 195 low earnings predictability firm events) in our standard univariate event study tests. In the current study, the full NASDAQ sample results and the fourth quarter results (available from authors) yield the same conclusion. 14 The increase in the adverse selection cost (AAC) around an earnings announcement is statistically and economically significant for the low earnings predictability firms. The estimation period AAC of $1.00 as a percentage of the estimation period mean price (average of the bid and ask price) of $22.20 is 4.51% for low earnings predictability firms, while the estimation period average AAC of $.99 as a percentage of the estimation period mean price of $38.19 is only 2.62% for high earnings predictability firms. The average increase in the ACC for the high earnings predictability firms is 14 cents on day −1 and 21 cents for day 0. On the other hand, for the average low earnings predictability firms the average increase in the ACC is 50 cents on day −1 and 61 cents on day 0, a considerable difference. Our calculations are consistent with Krinsky and Lee [1996, page 1533], who find that the adverse selection cost for an average stock with a price of $38.26 increases by 13.20 cents per round trip. EARNINGS PREDICTABILITY 579 and unexpected volume and return. The results are summarized in table 3, panel B.15 In examining our control variables, we note that the earnings surprise coefficient is positive but not significant. The number of market-makers variable, however, has a significant coefficient opposite in sign to that expected. This finding suggests that as market-maker competition increases, the adverse selection cost of the spread associated with information asymmetry increases. This result is inconsistent with our theoretical predictions but supports Christie and Shultz [1994]. Both abnormal volume and return are highly significant in the predicted direction at the 1 percent level. The other control variables, reporting lag and firm size, are not significant at conventional levels. The estimates of α2 and α3 , the coefficients associated with the earnings predictability variables, are both positive as expected. Also, the magnitude of the coefficients increases as the earnings predictability decreases (i.e., α2 < α3 ). Finally, the coefficient associated with the lowest predictability group (group 3) is significant at the 5% level. Consistent with our hypothesis, this result confirms that the adverse selection cost on average increases significantly around the earnings announcement for lower earnings predictability firms compared to higher earnings predictability firms after controlling for firm specific factors. This occurrence suggests that there are relatively higher levels of information asymmetry associated with firms with lower earnings predictability around quarterly earnings announcements. Our final test examines whether earnings predictability affects the bid-ask spread at times other than earnings announcement periods. In this analysis, we examine the total bid-ask spreads for our NASDAQ firms and predict that firms with more predictable earnings may also have lower bid-ask spreads in non-announcement periods. We use our group classification of firms to examine the effect of earnings predictability on the total bid-ask spread during non-announcement periods. The results in table 4 indicate a mean percentage spread of 0.016 for the high predictability group. The low earnings predictability firms have percentage spreads that are 0.008 higher on average than the high predictability group, the increase being significant at the 0.01 level. This difference represents a 51 percent increase in the spread relative to the high earnings predictability firms. The persistence of this difference is illustrated in figure 1 where we plot the mean percentage spread for each of the 589 trading days for both the high and low predictability of earnings groups. This figure shows that on almost every trading day we examined, the low predictability of earnings 15 In comparing the mean-adjusted bid-ask spread metric to the adverse selection cost estimate, we find a non-significant relation between the cumulative mean-adjusted spread, predictability of the earnings signal and the control variables. This suggests that the mean-adjusted bid-ask spread is not a proxy for adverse selection cost. 580 J . AFFLECK - GRAVES, C . M . CALLAHAN, AND N . CHIPALKATTI TABLE 4 OLS Estimation of the Time Series Analysis of the Percentage Bid-ask Spread a from 9/1/88 to 12/31/90, 589 Trading Days (the Non-Announcement Period) Results for High b , Medium c and Low d Predictability Groups e Model: PSPRDg,d = α1 + α2 (QE 2g,d ) + α3 (QE 3g,d ) + α4 (Y 90g,d ) + τg,d Indicator Variablesc Intercept QE 2 QE 3 Y 90 Number of Observationsc F -Statistic Prob Value Adjusted R2 Expected Sign Estimated Coefficient t-Statistic + + + 0.016 0.010 0.008 0.009 81.36∗∗ 33.31∗∗ 26.95∗∗ 36.67∗∗ 1,767 865.15 0.00 0.60 a Firms are classified into an earnings predictability group based on both the mean standardized absolute value consensus analysts’ forecast error (SAFE ) and dispersion of forecasts (DAF ) over the period 1984– 1989. SAFE is the absolute value of primary annual earnings per share before discontinued operations, extraordinary items and cumulative effects of an accounting change (COMPUSTAT annual item #58) minus the first consensus annual forecast dated after the year y −1 10-K filing date, standardized by primary annual earnings per share defined per the numerator. DAF is dispersion of analysts’ forecasts for the first consensus annual forecast issued after the year y −1 10-K report filing date using the standard deviation of analysts’ forecasts as reported by I/B/E/S, deflated by the absolute value of the first consensus annual forecast dated after the year y −1 10-K filing date. The firm classification scheme for the earnings predictability scoring requires benchmark NASDAQ sample medians for SAFE and DAF. To determine the benchmarks for the time period 1984–89, we calculate the mean standardized absolute forecast error (equation 2 in the text) and the mean relative dispersion of analysts’ forecasts (equation 4 in the text) for all NASDAQ firms with forecast and financial data available on the COMPUSTAT and I/B/E/S tapes with an annual earning announcement date on COMPUSTAT or DJNR (known 10-K filing date). Based on the specified criteria, the NASDAQ sample medians for SAFE and DAF are based on 614 firms and the computed cross-sectional medians are 0.68 and 0.11. We then use these NASDAQ medians to assign an earnings predictability score to each firm event (2,941) in our sample. b Firms classified in the highest predictability group (1) have both the average absolute forecast error and average dispersion over the period 1984 to 1989 less than the respective NASDAQ sample medians for the same metrics. c Firms classified in the medium predictability group (2) have average absolute forecast error less than the NASDAQ sample median for SAFE but average dispersion greater than the NASDAQ sample median for DAF over the period 1984–89 or average absolute forecast error greater than the NASDAQ sample median for SAFE but average dispersion less than the NASDAQ sample median for DAF over the period 1984 to 1989. d Firms classified in the lowest predictability group (3) have both the average absolute forecast error and average dispersion over the period 1984–89 greater than the respective NASDAQ sample medians for the same metrics. e Based on our earnings predictability classification scores (high, medium, and low), three portfolios of firms were formed on each trading day over a non-announcement period, 9/1/88 to 12/31/90 excluding earnings announcement dates, 589 trading days. We then computed the portfolio mean percentage spread (the total bid-ask spread deflated by the average price at the close of trading on trading day d) for each earning predictability group on each of the 589 trading days in the non-announcement period. f Definition of variables: PSPRDg,d : the mean percentage bid-ask spread, the logarithm of the difference between the ask price for firm i and the bid price for firm i deflated by the stock price for firm i (defined as the average of the bid and ask prices) at the close of each trading day for each earnings predictability group. QE 2g,d : 1 if the firm is in the medium earnings predictability group (i.e., with score 2) and 0 otherwise. QE 3g,d : 1 if the firm is in the low earnings predictability group (i.e., with score 3) and 0 otherwise. Y 90g,d : 1 if the trading date is in 1990 and 0 otherwise. τg,d : the assumed normally distributed random error term. ∗ and ∗∗ indicate statistical significance at the 0.05 and 0.01 levels, respectively (two-tailed tests). firms has higher average percentage spreads than the high predictability of earnings firms. These results suggest that earning predictability may have permanent and substantial effects on the bid-ask spread, and hence the firm’s cost of equity capital. EARNINGS PREDICTABILITY 581 FIG. 1.—Based on our earnings predictability classification scores (high and low), three portfolios of firms were formed on each trading day over a non-announcement period, 9/1/88 to 12/31/90 excluding earnings announcement dates, 589 trading days. We then computed the portfolio mean percentage spread (the total bid-ask spread deflated by the average price at the close of trading on day d) for each earning predictability group on each of the 589 trading days in the non-announcement period. 7. Conclusions This study examines the bid-ask spreads of 247 National Association of Securities Dealers Automated Quotations (NASDAQ) firms from 1985–90. We investigate the association between earnings predictability and the behavior of the adverse selection cost of the bid-ask spread around quarterly earnings announcements. Consistent with our prediction, we find an increase in the adverse selection cost of the bid-ask spread on the trading day of and the trading day prior to quarterly earnings announcements for NASDAQ firms with less predictable earnings. In contrast, we find no evidence of a significant change in the adverse selection cost of the bid-ask spread around quarterly earnings announcements of firms with highly predictable earnings. Our findings persist after controlling for price and volume movements, as well as other firm specific factors associated with the market response to earnings announcements. We also investigate the cost of equity capital implications of our findings and examine whether earnings predictability affects total bid-ask spreads in non-announcement periods. We find that firms with relatively less predictable earnings have consistently higher total bid-ask spreads across time than firms with more predictable earnings. This finding suggests that a firm with relatively less predictable earnings will have a higher cost of equity capital than a comparable firm with more predictable earnings. 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