Y. Turganbayev (D. Serikbayev East Kazakhstan state technical university, Kazakhstan ) Y. Batalov (D. Serikbayev East Kazakhstan state technical university, Kazakhstan ) S. Rakhmetullina (D. Serikbayev East Kazakhstan state technical university, Kazakhstan ) N. Denisova (D. Serikbayev East Kazakhstan state technical university, Kazakhstan ) THE MODEL OF ESTIMATION OF THE ROLE OF HUMAN CAPITAL IN ECONOMIC GROWTH OF KAZAKHSTAN REGIONS This paper tests empirically the importance of human capital for economic growth of a sample of Kazakhstan regions over the period 2001-2007. Human capital is treated as one of production factors. Two types of production functions are considered, in which human capital enters as input. The panel regression results show the positive and significant role of human capital in economic growth of Kazakhstan regions over the considered period. Keywords: human capital; role of human capital; the modelling; the production function;, economic growth. 1. Introduction Factors which influence economic growth of regions of a country are numerous, ranging from the geographical conditions to infrastructure development, from the availability of physical capital and labour force to their quality and structure. Besides, it appears that growth factors influence more developed and less well developed countries in different ways. However, many growth theories emphasize the role of human capital as an engine of economic growth. In spite of diminishing returns from physical capital, which is considered a main growth factor in the neoclassical growth theory, many countries, including the United States and some European countries, have experienced continued growth for more than one hundred years. The commonly accepted explanation for this fact is “... the expansion of scientific and technical knowledge that raises the productivity of labour and other inputs in production” (Becker 1993, p.24). Denison (1985) calculated that a quarter of the US per capita income growth during 1929-1982 was caused by an increase in the stock of human capital. The impressive economic development of Japan, South Korea, Taiwan, Singapore, and other countries in recent years also illustrates the significance of human capital to economic growth. These countries grew rapidly relying only on their labour force without having natural resources, and investing huge money in human capital. In this paper, the human capital dimension is investigated across the regions of Kazakhstan to establish the possible role and linkage of human capital with their economic growth. The purpose of this paper is to test empirically the importance of human capital for economic growth of a sample of Kazakhstan regions over the period 2001-2007. In this, we try to contribute to the solution of the fundamental problem of growth theory, which consists in finding the conditioning factors, which explain better the growth patterns across countries and regions. 2. Literature Review 2.1. Conceptual Definitions of Human Capital. The notion of human capital appears in the second half of the twentieth century due to the publications of Theodore Shultz and Gary Becker (Schultz 1961, Becker 1964). According to them, human capital is determined by the aggregation of investments in activities that increase an individual productivity in the labour market, such as health, education, migration, and on-the-job training. This definition of human capital has been widened to include non-market activities. For instance, Laroche, Mérette and Ruggeri (1999, p.89) give a broader definition of human capital: “Human capital is the aggregation of the innate abilities and the knowledge and skills that individuals acquire and develop throughout their lifetime.” There are also many other definitions of human capital. For example, Korchagin (2005, p.21) gives a wider definition of human capital including an environment, in which human capital operates: “Human capital is an intensive complicated productive factor of the development of an economy and society, which includes labour resources, knowledge, instruments of intellectual and managerial labour, an environment of living and intellectual work, providing effective and rational operation of human capital as a productive factor of the development.” In its ability to be a productive factor, human capital is similar to physical capital. However, there are significant differences between these notions. The main distinction from physical capital is the fact that “...you cannot separate a person from his or her knowledge, skills, health, or values the way it is possible to move financial and physical assets while the owner stay put...” (Becker 1993, p.16). Laroche, Mérette and Ruggeri (1999) highlight another set of the differences between these two types of capital with respect to property rights and marketability, accumulation, depreciation, returns, financing and taxation. Another difference between human and physical capital is the way of their measurement. While the stock of physical capital is measured by its cost, the measurement of human capital is a rather ambiguous task. 2.2. Measurement of Human Capital Since economists recognise human capital as one of the crucial economic growth factors, it is highly important to measure accurately its stock and influence on economic processes. The definition of human capital as a stock of knowledge, health, skills, experience, and culture embodied in individuals that are used for the maintenance of social, personal, and economic welfare assumes impossibility of developing of the uniform exact approach to measurement of the human capital. All possible estimates of human capital must be indirect because of the intangible nature of human capital. There are three main approaches to the measurement of the amount of human capital: “cost-based”, “income-based”, and “educational stock-based” (Le, Gibson and Oxley 2003). All the approaches to measure human capital have their advantages and drawbacks. However, in this paper, taking into account data availability and possible biases caused by these disadvantages, we use educational stock-based approach to measure human capital of Kazakhstan regions. As education is at the core of the human capital notion, the educational stock-based approach of its measuring is the most popular method among the researchers. There are several proxies within this framework, which are usually used to assess the human capital stock such as adult literacy rates, school enrolment ratios, educational attainment levels, and average years of schooling (Wößmann 2003). In the framework of educational stock-based approach, the most commonly used and popular proxy of the human capital stock is average schooling years and levels of educational attainment (Benhabib and Spiegel 1994, Gundlach 1995, Islam 1995, O’Neill 1995, Temple 1999, Barro 1997, 2001, Krueger and Lindahl 2001, Barro and Sala-i-Martin 2003). The schooling average years quantify the accumulated educational investment embodied in the current labour force. It is really a stock variable, and it considers the formal educational attainment obtained by the labour force, which takes part in the current production process. 2.3. Human Capital and Economic Growth The role of human capital in economic growth process has been extensively studied in the literature (Nelson and Phelps 1966, Lucas 1988, Romer 1990, Azariadis and Drazen 1990, Freire-Serén 2001, Temple 2001a, 2001b, and others). These studies specify two channels through which human capital can influence growth. Firstly, human capital can be treated as one of the factors of production (Mankiw, Romer and Weil 1992, Coulombe and Tremblay 2001, Abu-Qarn and Abu-Bader 2007, Vinod and Kaushik 2007). In this sense, the accumulation of human capital is assumed to generate directly the growth of the output. Secondly, human capital can influence the growth through the total factor productivity, namely raising technical progress, since education eases the diffusion and adoption of new technologies (Benhabib and Spiegel 1994, Islam 1995, Nelson and Phelps 1966). On the other hand, there is no common opinion among researchers on the important question: “What is more significant for economic growth: the accumulation of human capital or its stock? In this regard, Aghion and Howitt (1998, p.327) distinguish two approaches to modelling and analysing the link between human capital and growth. “The first one was initiated by Lucas (1988) and inspired by Becker’s theory of human capital. It describes the economic growth as being driven by the accumulation of human capital. So that the differences in growth rates across countries are mainly determined by the differences in accumulation of human capital over time of those countries. The second approach, which stems from the work of Nelson and Phelps (1966) and finds its continuation in Schumpeterian growth literature is based on the idea that economic growth is driven by the stock of human capital , which is a decisive factor in a country’s ability to innovate or catch up with more advanced economies.” 3. Human Capital as a Factor of Economic Growth of Kazakhstan Regions 3.1. The Model and Methodology In this paper we study the human capital's impact on economic growth of Kazakhstan regions considering it as a factor of production. The used methodology is the inclusion of human capital into the production function. The micro-level findings that the educational attainment of workers determine their marginal products serve as an argument for this methodology (Fleisher and Wang 2001, 2004, Fleisher et al. 2010). Thus, the aim is to study direct effect, according to which employees with higher level of human capital have a higher marginal product in comparison with those who have achieved lower level of human capital. In order to study the direct effect of human capital on output, we consider two aggregate production functions, which take the Cobb-Douglas form with physical capital and labour taken as inputs. The distinctive feature of the first function is that labour input includes two categories: (1) workers with higher education; (2) workers with below higher education (Fleisher, Li and Zhao 2010). π½ π½β π½π π’ππ‘ πππ‘ = π΄ππ‘ πΎππ‘π πΏβππ‘ πΏπππ‘ π (1) where πππ‘ is output, πΎππ‘ is capital, πΏβππ‘ is the quantity of employees with higher education or above, πΏπππ‘ is the quantity of employees who have below higher education, π’ππ‘ is a disturbance term, for region π = 1,2, … , π from years π‘ = 1,2, … , π. Parameters π½π , π½β , π½π are the elasticities of corresponding factors with respect to output, which are estimated by the regression procedure. Next, following Mankiw, Romer and Weil (1992), we consider another production function, which includes physical capital πΎ, labour πΏ, and human capital β as inputs: π½ π½ π½ πππ‘ = π΄ππ‘ πΎππ‘π πΏππ‘π βππ‘β π π’ππ‘ (2) Again, the corresponding elasticities of inputs π½π , π½π , π½β are estimated using regression method. 3.2. Data We take the data on GRP and investment from various years of the Regions of Kazakhstan statistical issue (1993-2009). These data are deflated over time by an official GDP deflator with 1993 taken as a base year. In assessing the level of physical capital input to the production function, we use the conventional assumption that it is proportional to the capital stock level. To assess the last the perpetual inventory method (PIM) is usually employed (Abu-Qarn and Abu-Bader 2007). This method can be expressed by the following equation: πΎππ‘ = (1 − πΏ)πΎπ,π‘−1 + πΌππ‘ (3) where πΎππ‘ is the capital stock of π-th region at time π‘, πΌππ‘ is the real investment in fixed assets, πΏ is the depreciation rate, assumed to be 5% (Miyamoto and Liu 2005). We deflate gross investment in fixed assets available in Regions of Kazakhstan (1993-2009) and calculate real investment flows πΌππ‘ . There are some controversies regarding the deflator used for deflating investment series (Islam, Dai and Sakamoto 2006). For example, Ezaki and Sun (1999, p.44) use the “price index of investment in fixed assets,” which is the weighted average of the “producer price index of machine building industry” and the “total output price index of construction” at the country level. The weights 1/3 and 2/3 are taken quite arbitrary. Another approach is to use the official deflator for the formation of gross fixed capital, but the data on this deflator has only been available since 1996. Therefore, we take the GDP deflator, available in the Statistical Yearbook of Kazakhstan (1993-2009), to deflate investment series. The year 1993 is taken as the benchmark for the deflator. As an initial stock of capital the balance (book) cost of fixed assets as of 1993, available in Regions of Kazakhstan (1993-2009), is taken. In order to diminish the influence of the initial capital stock on the calculated series, the capital stock is computed from 1993, even though in the model, these data are used from 2001. The data on employed population with higher education serving as a measure of the level of human capital are given by the Economical Activity of the Population of the Republic of Kazakhstan statistical issue (1993-2009). Unfortunately, these data are available only for the period 2001-2007 that essentially confine the period of the study of the influence of human capital on economic growth of Kazakhstan regions. 3.3. Empirical Results In order to study the influence of human capital on economic growth of Kazakhstan regions, we start with the production function (1), which considers physical capital and two types of labour as inputs. Having the panel data of GRP, physical capital, and two kinds of labour force across Kazakhstan regions over the period of 2001-2007, first, we choose whether fixed or random effect model is more appropriate to analyze them. In doing this, we use a Hausman test, in which the null hypothesis is that the preferred model is random effects; while the alternative is that the preferred model is fixed effects (Hausman 1978). This test checks the correlation between unique errors and regressors. Under the null hypothesis, they are not correlated. We run the Hausman test using the Stata command hausman fixed random. As regressors logarithms of physical capital and two types of labour are taken. The results of its implementation are presented in Table A.1. As the value of the ππππ > πβπ2 is equal to 0.1759, we can not reject the null hypothesis of no correlation between unique errors and regressors. This means that the random effects model is more preferable in this case. Afterwards, we run Breusch-Pagan Lagrangian multiplier test (Breusch and Pagan 1979), which helps to choose between the random effects regression and a simple OLS regression. We use the Stata 10 command xttest0 after running the random effects model. The results of this test shown in Table A.2 allow to conclude that the null hypothesis of the test can be rejected in favour of the alternative, meaning that there is a panel effect and the random effects model is more preferable than the simple OLS regression. Next we use the Wooldridge test for the presence of serial correlation in our data (Wooldridge 2010) applying the xtserial Stata command. The results of this test show the rejection of the null hypothesis of the absence of autocorrelation in favour of the alternative of the first order autocorrelation. Thus, to study the influence of human capital on the output of Kazakhstan regions, we apply the random effects model with first-order autocorrelation property of standard errors. We use the Stata 10 command xtregar with random effects option to run this regression. Table 1: Random effects model regression with the property of first-order autocorrelation of standard errors (production function with two types of labour) [95% Conf. LnGRP Coef. Std. Err. z P>|z| Interval] LnCapital .685 .043 15.79 0.000 [.600, .770] LnHigher .291 .058 5.06 0.000 [.178, .404] LnNonHigher .116 .064 1.81 0.070 [-.009, .242] _cons .117 .512 0.23 0.819 [-.886,1.121] rho_ar .658 (estimated autocorrelation coefficient) sigma_u .119 sigma_e .092 rho_fov .627 (fraction of variance due to u_i) theta .435 Error! Reference source not found. reports results of the random effects model estimation of the region-level production function (1) with two kinds of labour grouped according to the educational accomplishment. The capital input elasticity estimate is positive and significant at 1% confidence level and equals to 0.685. The estimate of the elasticity of more educated labour is equal to 0.291 and is significant at 1% confidence level, while the estimate of the elasticity of less educated labour is equal to 0.116 and is significant only at 7% confidence level. The former estimate is larger than the latter in 2.5 times. In this specification, estimates of elasticities of three inputs: physical capital and two types of labour sum up to 1.09 that confirms the hypothesis of constant returns to scale. Thus, the human capital expressed as the number of employees with higher and below higher education enters positively and significantly in the production function of the type (1). The regression results show that the elasticity of the labour force with higher education is 2.5 times higher than of the elasticity of the labour force with below-higher education that confirms the importance of human capital as a production factor. Next, we study the role of human capital in the economic growth of Kazakhstan regions using production function of the type (2). Again, we apply several econometric tests to determine what type of regression is more appropriate for the panel data. The results of these tests are presented in Tables A.3-A.5. According to these tests we use the random effects model with first-order autocorrelation property of standard errors. This model is realized by the xtregar Stata command with random effects option. Table 2: Random effects model regression with the property of first-order autocorrelation of standard errors (production function with labour and human capital) [95% Conf. LnGRP Coef. Std. Err. z P>|z| Interval] LnCapital .688 .043 15.89 0.000 [.603, .773 ] LnLabour .413 .070 5.92 0.000 [.276, .550] Ln_h_it .217 .075 2.88 0.004 [.069, .365] _cons -1.087 .514 -2.11 0.035 [-2.095, -.078] rho_ar sigma_u sigma_e rho_fov .662 .120 .092 .634 (estimated autocorrelation coefficient) (fraction of variance due to u_i) theta .438 Table 2 reports regression results of the random effects model with the property of firstorder autocorrelation of standard errors of the production function of the type (2). The estimates of the elasticities of all three inputs: physical capital, labour, and human capital, are positive and significant at 1% confidence level. The estimate of the human capital variable, approximated by the percentage of employed population with higher education, is equal to 0.217. 4. Conclusion Thus, to study the direct effect of human capital on economic growth of Kazakhstan regions we considered two types of production function. In the first specification, the labour input was divided into two types: workers with higher education and workers with education below higher. The regression results of this specification, within the framework of the random effects panel model, showed an evidence of positive and significant direct effect of human capital on the production function resulted from the workers with higher education rather than from those with less than higher education. In the second specification, the Cobb-Douglas type production function along with physical capital contained labour and human capital variables. Again the estimates of the elasticities of all three inputs were positive and highly significant. Thus, human capital, measured using educational stock-based approach and considered as one of production factors, played a significant positive role in economic growth of regions of Kazakhstan over the period of 2001-2007. References: Abu-Qarn, A.S., Abu-Bader, S. (2007). 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APPENDICES: Table A.1: Hausman test to check whether fixed or random effects model is more appropriate (production function with two types of labour) Coefficients (b) (B) (b-B) sqrt(diag(V_b-V_B)) fixed random Difference S.E. LnCapital .844 .663 .181 .075 LnHigher -.037 .309 -.3465 .137 LnNonHigher -.245 .057 -.302 .181 Notes: b = consistent under Ho and Ha; obtained from xtreg B = inconsistent under Ha, efficient under Ho; obtained from xtreg Test: Ho: difference in coefficients not systematic chi2(3) = (b-B)'[(V_b-V_B)^(-1)](b-B) =4.94 Prob>chi2 = 0.1759 (V_b-V_B is not positive definite) Table A.2: Breusch and Pagan Lagrangian multiplier test for random effects (production function with two types of labour) Var sd = sqrt(Var) LnGRP .362 .602 e .011 .106 u .023 .153 Notes: Test: Var(u) = 0 chi2(1) = 109.83 Prob > chi2 = 0.0000 Table A.3: Hausman test to check whether fixed or random effects model is more appropriate (production function with labour and human capital) (b) (B) (b-B) sqrt(diag(V_b-V_B)) S.E. fixed random Difference LnCapital .797 .667 .129 .073 LnLabour -.005 .379 -.384 .270 Ln_h_it .066 .259 -.193 .096 Notes: b = consistent under Ho and Ha; obtained from xtreg B = inconsistent under Ha, efficient under Ho; obtained from xtreg Test: Ho: difference in coefficients not systematic chi2(3) = (b-B)'[(V_b-V_B)^(-1)](b-B)= 6.72 Prob>chi2 = 0.0813 Table A.4: Breusch and Pagan Lagrangian multiplier test for random effects (production function with labour and human capital) Var sd = sqrt(Var) LnGRP .362 .602 e 011 .107 u .023 .153 Notes: Test: Var(u) = 0 chi2(1) = 110.14 Prob > chi2 = 0.0000 Table A.5: Wooldridge test for autocorrelation in panel data (production function with labour and human capital) F(1,15) 27.598 Prob > F 0.0001 Notes: H0: no first-order autocorrelation