'^^^^ 28 414 \1l\'S^ I ALFRED P. WORKING PAPER SLOAN SCHOOL OF MANAGEMENT MORAL HAZARD, BORROUING, LENDING AND RICARDIAN EQUIVALENCE Julio J. Rotemberg Working Paper #1931-87 September 1987 MASSACHUSETTS INSTITUTE OF TECHNOLOGY 50 MEMORIAL DRIVE CAMBRIDGE, MASSACHUSETTS 02139 NOV 12 1987 M»BA»> «d WORAL HAZARD, BORRQUIING, LENDING AND RICARDIAN EQUIVALENCE Julio J. Rotemberg Working Paper #1931-87 September 1987 MORAL HAZARD. BORROWING. LENDING AND RICARDIAN EQUIV ALENCE Julio .1. Rotomberg'' September 1987 Abstract In this paper I random payoffs study privately optimal contracts when individuals face if they expend unobservable effort. Full ins\iranre eliminates the incentive to work so it is generally tioI optimal. Optimal contracts which tradeoff insurance and the need to preserve incentives are studied. In a simple model I show that these optimal contracts can be implemented using only assets, loans and the instil ution of iiankcruptcy Ricardian equivalence even with with taxes that are a function of income holds locally but not globally fails in this model. current tax cuts can easUy lead to Where Ricardian equivalence reductions in current consumption. '•' Sloan School of Management, MIT. discussion and the NSF I wish to tliank Olivier Blanchard for for financial support. The existence taken to mean that Ricardian equivalence must has lost some of Yotzu7,uka( 1987) fail. This a priori argument force since the papers of Hayaslii (1986) and its . been of imperfections in financial mari^ots lias often They show that the wedge between lending and borrowing rates caused by adverse selection in credit markets does not necessarily imply a failure of Ricardian equivalence. markets that has been adduced to A different failure in financial imply absence of Ricardian equivalence by Barsky, Mankiw and Zeldes (1986) following on work by Chan (1983), impossibility, due to moral hazard, of selling human capital. models income insurance suceeds in is the is In their not privately provided because an individual who Then, government purchasing insurance would stop working. instituted linear income taxes provide some otherwise vinavailable insurance which generally affects current consumption. One weakness of these papers is that they do not consider optimal insurance contracts between individvials, they simply postulate that certain contracts are available and exclude others^^. In this paper is it shown that in a relatively simple model the existence of optimal contracts, in the presence of moral hazard, restores Ricardian equivalence While moral hazard prevents full insurance, is locally. still Small government insurance schemes are then simply offset by possible. changes some insurance even in this privately programs have the effect optimal contracts. As provided insurance. of Larger reducing effort even a result tax cuts social insurance in the equilibria accompanied by increases with in futiire taxes that are very progressive (i.e. provide a great deal of insurance) can, by reducing future effort, and hence An reduce the individual's permanent income his current consumption. objection to this line of analysis is that such privately supplied optimal insurance schemes are simply not observed. The simple example 3 developed in paper casts some doubt on this this criticism optimal contract can be implemented using only the which we observe regularly. three institutions: it In particular, must be possible of institutions implementation requires only borrow, to menu because the to lend and to go In implementing the optimal contract via these institutions the bankrupt. paper follows the lead of Gale and Hellwig (1985) who show that debt contracts with bankcruptcy can be optimal contracts model of asymmetric information. In their observabUity of income which leads model it in is a rather different the costly to these contracts. Implementation via these borrowing, lending and bankcruptcy has some appealing features. First, people will be observed borrowing and lending simultaneously even though interest rates on loans exceed interest rates on assets. It rates that is betweeen lending and borrowing of course the difference is viewed as suggesting liquidity constraints as well as the failure of Ricardian equivalence (Pissarides (1978), Buiter (1985)). Second, individuals wUl be genuinely credit constrained, they would to borrow more from doing individual so, is Not only are they prevented at the existing lending rate. no additional borrowing solvent. This is a more is like possible even though the strict version of credit constraint than the one shown to hold by Gale and Hellwig (1985) since in their model, as in that of Keeton (1979 ch.2) more would be lent, albeit at higher interest rates. The paper proceeds as follows. optimal contract are presented. using assets and in this liabilities. In Section Section III is II the model and the devoted to implementation Section IV discusses Ricardian equivalence model while Section V concludes. II I Their The model consider people who utility in the initial U(Co) ^ where U pEU(Ci) is a - live for period is two periods labeled zero and one. given by: k6 (1) concave function, Cj is consumption expectations conditional on information available 6 is and in the an indicator variable which takes a value of one is in period initial if effort E takes i, period and is expended zero otherwise. Effort is expended for the disutility of k, at the beginning of period one. who expend individuals income Yg with probability With probability tt. and they earn the same Income In compensation effort earn a high level of (1-tt) they are unsuccesfull they would earn without expending effort. Yj-, These realizations can be thought of as uncorrelated across individuals. As unobservable while income and consvimption in Holmstrom (1979), effort are observable. A contract is Individuals also have an endowment specifies transfers institutions in the initial period, which depend on the realized Wq the first period. in between individuals and financial as well as transfers in period one level of income. Equivalently , and with some gain in convenience, one can view them as specifying three levels of consumption Cq, Cg and Cj, which correspond two possible levels of income respectively. to the initial Effort will be period and to the expended if contract stipulates that: TTfU(Cg) - U(Cb)] ^ k (2) the while not will It the inequality If reversed. is Financial intermediaries (which can be thought of as foreigners) are Such risk neutrality emerges risk neutral and have a dicount factor R. naturally (1985). If Thus the intermediaries are willing to sign any contract whose Therefore, gross rate of return equals R. will be high (Wo - Judd the Income uncertainty disappears In the aggregate as In Is contracts wLLl be offered which satisfy: z, Co)R the probability that income if = z(Cg Yg) - (l-z)(Cb + - Yb) (3) Optimal contracts maximize (1) subject to (3) and the constraint that effort will be otherwise z effort to be expended (I.e. equals zero. expended any contract). in I z now equals - if and only any optimal contract (or even U(x + Yb)] - is k assumed all that optimal contracts Involve effort Suppose an individual Then, by expending effort values of x. It is is: (4) changes by the amount on the LHS that this change be positive for throughout > reaches period one with assets equal to x. utility satisfied; the absence of in to hold This condition can be interpreted as follows: expected is (2) if briefly give a sufficient condition for This condition which Vx>0: TT[U(x + Yg) it) of (4) To see . I am requiring that this implies sufficient to note that contracts without effort have z equal to zero in (3) so that optimal contracts are simply risk free lending contracts. satisfied, utility Hence, his if (4) is can be Increased by offering the same size loan and 6 allowing the individual to keep any extra income that lie earns by expending effort. Given expending effort (4) Expending costlessly monitored. is Suppose effort could be optimal. effort would still bo optimal but, since individuals are risk averse and financial intermediaries are risk neutral, consumption would not depend on whether the effort was succcsfull. other words Such full have the Cg would equal C^ and insurance is the individuals would be fuUy insured. obviously impossible with unobservable effort; we The optimal contract will achieve as much insurance as possible given the need to induce effort. (2) and optimal risk usvial tradeoff of incentive compatibility sharing. In It thus will is make the constraint hold with equality. Using and (2) (3) in (1) and differentiating, the optimal contract satifics: U'(Co){l - TT[U'(Cb)/U'(Cg) - 1]1 = pRU'(Cb) (5) where primes denote derivatives. Equation (2), (3) and can be (5) solved for the three levels of consumption although that will not be done here. Ill Implementi n g the Optimum with Debts, Assets and Ba nkcruptcy Before implementing the equilibrium with debt and assets convenient to interpret the optimal contract in insurance terms. This can be done as follows. it is more traditional asset- The individual can be 7 thought of as carrying ovpr an amount of risk free assets A equal Cq) Consumption . in period one Cg = AR . Yg > Xg Cb = AR * Yb ^ Xb where the X's can be though is to (Wq" then: of as transfers. By (3) these transfers represent simply an actuarially fair insurance policy since: irXb (i-^)Xg * = 0- (6) Moreover, since as much insurance relatively low, Xb is Is provided as possible and Yb is positive. In the debt-assets implementation the individual carries over instead an amount of assets equal A' = A the maximum D = Xb which is A'such that: Xb/R + so that to Cb is (7) simply A'B. + Yb- Debt obligations D, which are defined as the person owes to the financial intermediary are equal to: - Xg positive (8) by the argument given above. assets and liabilities supports tlie optimal contract as long as bankcruptcy prevents consumption from falling below Cb- such that individuals In This combinations of Bankruptcy is an institution debt can ask for protection from their creditors, 8 debts are forgiven as long as the individuals's consumption level This threshold a certain threshold. economy consisted payoffs, is here required to equal the legislated threshold If . below C]-,. the If of ex-ante identical individuals with uncorrelated such a threshold would be have a certain appeal avithorities is mechanism for forgiving debt is to distressed different, to legislative some other borrowers would have be to implemented. With bankcruptcy, when are fully paid that they are paid probability be it is Yg. must exceed R. Yj, while is So the gross return on debts the event in when they are actually paid must This can be seen by noting that since A equals (Wq-Cq) R/tt. difference between A' and they Since debts are only paid with the gross return on debts tt, when income the debts are forgiven A must equal the amount exchange for the the financial intermediary gave the indlvidvial in payable only in the good state. Moreover, using (6), tiie , claim of (7) D which and (8) it is is readily established that D/(A'-A) equals R/tt. If and is A is positive, liabilities of the implementation implies an overlap between assets (A'-A). The only reason assets exceed A period zero because the financial intermediary has also provided a loan. overlaps are commonplace as of the and minimum liabilities positive. is evident from table of financial assets for individuals Maintenance Experiment^. and liabilities who participated A negative A would be his other loans. Even when A an overlap of assets and 1 which to the lists maximum Such the ratio of assets the Denver Income in Of course, at the optimal contract A need not be a risk free "senior" loan intermediary could be sure to collect on even to in is if which the the individual defaults on negative, A' can be positive thus leading liabilities although, if A' is negative as well 9 only liabllltips will be observed. Before one can say that assets and it is necessary show to individuals would, in that if liabilities only assets and implement the contract liabilities the presence of the appropriate and select the appropriate levels of assets liabilities. were offered, bankcrupcy threshold, 1 deal first with the choice of assets then with that of liabilities. To whether the optimal find out whether, starting level of assets would be chosen, at the optimal allocation individuals would want I ask to either increase period zero consumption and reduce assets or viceversa. Because bankcrupcy these two decisions are somewhat different and must of be treated separately. Suppose that an individual decided in period zero and hold one less unit of A. Intermediary fall by R. is consumption by one unit to increase not collecting anything on the bad state, In its loan so consumption would Similarly in the good state the individual his obligation so constimption would by R. fall the is fully paying of Tht:s the change in utility Is^: U'(Co) - pR[^U(Cg) + (l-Tr)U(Cb)] < U'(Co){l + Tr[U'(Cb)/U'(Cg)-in pRTr[U'(Cg)-U'(Cb)l where the first inequality is due - pRfTTU(Cg)Ml-TT)U(Cb)] < (9) to the fact that lower In the good state than in the bad, the equality equation that characterizes optimal contracts (5) inequality strictly is due to the same reason as the bad for the individual. The reason = , first. is marginal utility is is obtained using the and the second So this change is that for a given Increase 10 in consumption in expected It period zero, optimal contracts provide for a smaller in utility in period one than do pure asset contracts. worth noting that inequalities such as is fall (9) have iioon defined as representing liquidity constraints by both Runkle (1987) and Zeldes (1985). Zeldes (1985) finds evidence that for relatively poor individuals this inequality holds strictly while Runkle (1987) using the same PSID data but different methods disputes this conclusion. Now consider reducing consumption of assets. period zero and raising the level in Since bankcruptcy aUows the individual to consume only extra assets do not secure increased consumption so only in the good state. change in utility -U'(Co) the bad state, consumption rises by R. In that state the they do So the is'': pTTRU'(Cg) ^ in Cj^, = = {-pU'(Cb) * TTpU'(Cg)[l-TT(l-U'(Cb)/U'(Cg))]}/0 p(l-iT)(-U'(Cb) * TT[U'(Cg)-U'(Cb)]l/<^ < (10) ^ = 1 + TT[U'(Cb)/U'(Cg) where the first equality is also unatractive. state - 1] obtained using (5) assets required by the optimal contract In the strongest possible sense; worse This change This occurs because extra assets are useless where they must be turned over strictly . to creditors. is is in thus the bad Hence, the level of the individually rational choice any deviation makes the individual off. Now consider are only relevant the choice of liabilities. if high income is Changes in period one debts realized since none of the debts are 11 paid Suppose the individual reduces the bad state. in his consumption in period zero and correspondingly carries fewer debts forward so consumption in the good state of period one corresponding change -U'(Co) Thus ^ this Is in utility pRU'(Cg) = increased by Using R/tt. (5), the is: p(l-TT)[U'(Cg)-U'(Ch)]/<^ makes the individual strictly worse < off. This means that the individual would like to increase his indebtness by one dollar and consume the proceeds consumption have to will This means that the inequality take place. be written would impose a is more zero and to the consumption during wLU be reversed so that all the debts would strict than It is He this. worth noting that the what has been derived, for instance (1985) in that additional credit wouldn't be extended any interest rate. in z falls (2) in The intermediary would never accept off. by Gale and Hellwig more dollar Thus strict credit constraint. credit constraint at Such an increase, however, lowers period zero. good state without any change in the the bad state. no effort tt/R in The reason is that if the individual owes even one the good state, he stops working and the equilibrium is destroyed. In conclusion, the implementation of the optimal contract has three empirically relevant features. For individuals, rates of return on assets are lower than those on liabilities. types of instruments. they are allowed Individuals nonetheless hold both Moreover, individuals would like to borrow more than to. While the implementation of the optimal contract with assets and liabilities appears in some ways natural one caveat is in order. The 12 implementation of the optimal contract The main take on more values^. of simultaneous assets and will be more complex when income can point of this section liabilities that the existence is the presence of bankcruptcy in simplifies the implementation of the optimal contract. IV Ricardian Equivalence In this section I consider government tax and transfer schemes which have an expected present discounted value of to depend on the of A transfer scheme . payments from the government GqR + zGg where z is allow these transfers 1 realization of income so that these transfers can in principle be distortionary Gg) 7,ero. + (l-z)Gb is thus a triplet (Gq, to individuals Gj^, which satisfy: = (11) again the probability that high income is earned. Contracts between financial institutions and individuals are entered upon after the G's become known. consumption Cq, Cg and Cj,. They Now still specify the three levels of for the financial intermediary to be willing to offer a given contract: (Wo * Go - Co)R which, using, offer the same maximize only if (1) (2) is menu = (11) z(Cg - Gg reduces to - Yg) (3). + (l-z)(Ch is " (12) Yfa) Optimal contracts subject to (3) and the condition that z and Gfa So intermediaries are willing of contracts as before. satisfied + is equal to zero otherwise. equal to Thus, if still it if in and to 13 equilibrium effort takes place, consumption intervention. (4) unaffected by the government is With government transfers, the condition corresponding to which ensures that effort Vx>0: TTfUCx+Yg+Gg) - Is U(x + Yb + Gb) The argument given below try to earn Yg. Moreover, expended (4) k - 1 > (13) ensures that if (13) holds, individuals holds there are exists nonzero government (4) if is: transfers which are such that (13) holds. These transfers can have progressive elements so that, for instance, Gg can be negative while G^ is positive. Yet, there are also transfer schemes which prevent (13) from holding. In the extreme case in which the transfers schemes are such that (13) holds with the inequality reversed for taking place. all x, the only equilibrium has no effort Siippose that even though (13) This can be seen as follows. holds with the inequality reversed intermdiaries are offering a contract in This means that which effort takes place. equality. if income So, is payments from the intermediary high than if it is low. Suppose deviating intermediary equalized payments In the (2) good state and raising them than U'(Cb) the individual is is to the individual are that, Yet, larger maintaining (3) a both states by lowering them bad. Since U'(Cg) is better off with this contract even somehow be kept working hard. reversed the individual in the in holds at least with smaller if he can because (13) holds with the inequality made even better off by giving up effort. Hence, intermediaries who offer contracts that involve no effort can take all the customers from intermediaries whose contracts require working hard. Government transfer shemes that eliminate effort have Gg lower than 14 Gb, they are progressive^. So, one form of intervention that can have this a cut in taxes at time zero followed effect is in the event by a small increase in taxes a large tax if Yg eliminates effort, lifetime income is lowered so that consumption at time ta.x cut lowers consumption unlike what zero falls Yjj and unambiguously. The is realized instead. Barsky, Manklw and Zeldes regard as the normal case in If this sciieme which the progressive income tax raises current corresponding increase in a consumption because reduces future consumption uncertainty'. it 15 V Conclusions This paper has two presence of assets and One foci. liabilities show that the simultaneoiis to is together with a certain kind of credit constraint can Implement an optimal contract. The other show that to is RIcardlan equivalence survives at least locally when markets are incomplete due to moral hazard. which failures in One question which arises whether other models is the credit market are derived from contracting difficulties can also explain the simultaneous existence of assets liabilities in and whether Ricardian equivalence would survive in and these models. It is worth stressing that reasons for credit rationing advanced by Keeton (1979) and Grossman and Weiss (1981) are not very compatible with the actual contracts that we see. One reason advanced by Jaffee and Russell (1976), (1986) and Yotzuzuka (1987) is for credit constraints Stiglitz and Weiss (1981), Hayashi that different otherwise indistinguishable borrowers have different propensities to go bankrupt. Yet, if insurance contracts were explicitely allowed in this adverse selection model and individuals were risk averse while intermediaries were risk neutral, any equUibriiim would include at least some individuals insured. In particular, who would be completely pooling equilibria would have everyone while separating equilibria would have full full insurance for insurance at least for the worst risks. Another reason for credit constraints advanced by Keeton (1979) and Stiglitz is and Weiss (1981) They note involved. be tempted to is more related to this paper since moral hazard that as interest rates increase individuals would undertake investements with higher risk but with lower 16 This induces credit rationing by making rises expected return. demand rates an unprofitable response to excess in when Yet, for loans. interest the potential actions of individuals affect the variability of returns the standard debt contract is very unappealing. Instead, to induce people to refrain from adopting needless risk, optimal contracts would specify that Individuals be penalized when outcomes which are unusual under more conservative strategies are observed. setup in Stiglitz This is particularly easy for the and Weiss (1987) were the risky and safe project differ only in the probability of the good outcome and in the size of the good outcome. To prevent the risky project from being undertaken sufficient to reduce consumption to zero project It Stiglitz income is the good outcome of the risky observed. may thus be costly observability of income which lies behind the Gale and Hellwig (1985) show that and Weiss (1987) analysis. is if observable only at a cost, the optimal contract actual debt contracts with bankruptcy provisions. when is it the borrower is a risk neutral firm. As is if identical to Their model applies only a result their inconsistent with joint holdings of assets and liabilities. model Such holdings might well arise, even when the only imperfection is is joint the costly observation of income when borrowers are risk averse individuals. It if may be tempting to conclude that, whatever the market imperfection, optimal private contracts have the structure of assets and liabilities then changes liabilities in taxes which resemble changes in people carry over can't have an effect. paper shows that this intuition is the level of assets and In some sense this only partially right since Ricardian equivalence does not hold globally. Therefore, whether Ricardian equivalence would carry over into a world in which income is imperfectly 17 observable It model is in Is an open question. worth pointing out that Ricardian equivalence holds this part because contracts are signed either after the government institutes balanced budget transfer schemes or because they are made contingent on such transfer schemes. transfer schemes are instituted after government policy. (1983) in which reason he doesn't explain, in is is government many contracts have been signed and This incompleteness randomness of course In practice, the contracts we observe rarely have clauses that Yet, in make them contingent on reminiscent of the work of Chan is introduced by the government which, for some not privately insured. models with simultaneous borrowing and lending there natural reason why, when the government signed contracts, the private sector governments action. The reason is be able at least in to undo the some sense, agents find themselves at corners since there are credit constraints. is instituted, suppose So, the government institutes a tax rebate financed by future taxes. contracts were signed after this program a acts after private agents have will not that, is If individuals would simply be able to borrow less and the scheme would have no effect. contracts are set in stone by the time the scheme is individuals would continue to avail themselves of the allowed to borrow so the allocation would change. If instituted, maximum they are The general analysis of the effect on Ricardian equivalence of letting the government act after contracts which are not contingent on government actions have been signed is left for further reseach. 18 FOOTNOTES This criticism applies more generally to most of the literature on 1 credit rationing including Jaffee and Russell (197G), Keeton (1979), In Stiglitz and Weiss (1981,1987), Hayashi (1986) and Yotzuzul<a (1987). their models people would like insurance yet only "borrowing" contracts are considered am grateful to David Runkle for providing the data on which these 2 I computations are based. 3 It is worth noting that reduced assets do not reduce the desire to work. Consumption falls by the same amount in both states so utility falls This means that by more in the low state where marginal utility is high. the difference in utility in the two states actually increases. Again, the increased assets do not impair effort since the increase in 4 consumption when the good state is realized is actually bigger when more assets are carried forth. Such more general optimal contracts are discvissed by Varian (1980) who 5 discusses insurance provided by an optimizing government but whose solution corresponds to optimal contracts which are privately supplied. 6 Budget balance dictates that the government note that the scheme will eliminate effort so that Gg becomes immaterial. The low (or negative) never actually takes place. transfer Gg 7 This normal case of course requires that U'" be positive. 19 REFERENCES Barsky, Robprt, N.Gregory Manklw and Stephen Zeldes "Ricardian : Consumers with Keynesian Propensities" American Economic Review , 1D86, 76, G76-91 Buiter, Wlllem Economic Policy , H.:"A Guide to Public Sector Debts and Deficits" 1985 Chan, Louis K. C. "Uncertainty and the Neutrality of Governenment : Financing Policy" Journal of Monetary Economics , 1983, 11, 351-72 Douglas, and Martin Hellwig: "Incentive Compatible Debt Gale, Contracts: The One-Period Problem", Review of Econ omic Studies, 52, 1985, 647-63 Hayashi, Fumlo: "Tests for Liquidity Constraints: A Critical Survey", NBER Working Paper # 1720 . 1986 Holmstrom, Bengt: "Moral Hazard and Observability", BeU. Journal of Economics , Jaffee, Spring 1979, 74-91 Dwight and Thomas Russell: "Imperfect Information, Uncertainty and Credit Rationing", Quarterly Journ al of Econom ics, Judd, Kenneth: "The Law of large Numbers with Random Variables", Journal of Economic Theory , 35, 40, a 1976, 651-66 Continuum 1985 of IID 20 Keeton, William: Equilibrium Credit Rationin g, Garland Press, NY, Pissarides, Cristopher A. "Liquidity Considerations in : Consumption" Quarterly Journal of Economics , the Theory 1979 of 1978 Runkle, David: "Liquidity Constraints and the Permanent Income Hypothesis: Evidence from Panel Data" Mimeo 1987 Joseph and Andrew Weiss: "Credit rationing Stiglitz, Imperfect Information", American Economic Review : , 71, in 1983, Markets with 305-18 "Macro-Economic Equilibrium and Credit Rationing", mlmeo, 1987 Yotzuzuka, Toshiki: "Ricardlan Equivalence in the Presence of Capital market Imperfections" Mlmeo MIT June 1987 Zeldes, Stephen: "Consumption and Liquidity Constraints: An Empirical Investigation" Wharton Working Paper #24-85 , November 1985 1813 C ^3 Date Due MIT LIBRARIES 3 TDflD D04 TEA 3bT