cash by any other name evidence on labelling from the uk winter fuel payment standard economic theory implies that the labelling of cash transfers or cash equivalents e g child benefits food stamps should have no effect on spending patterns the empirical literature to date does not contradict this proposition we study the uk winter fuel payment wfp a cash transfer to older households exploiting sharp eligibility criteria in a regression discontinuity design we find robust evidence of a behavioural effect of the labelling on average households spend 41 of the wfp on fuel if the payment was treated as cash we would expect households to spend approximately 3 of the payment on fuel

heterogeneous beliefs wealth distribution and asset markets with risk of default s t t u c i s t i s t s 0 subject to a sequence of budget constraints c i s t t 1 q s t 1 a i s t 1 y i s t a i s t

a general equilibrium model of portfolio insurance this article examines the effects of portfolio insurance on market and asset price dynamics in a general equilibrium continuous time model portfolio insurers are modeled as expected utility maximizing agents martingale methods are employed in solving the individual agents dynamic consumption portfolio problems comparisons are made between the optimal consumption processes optimally invested wealth and portfolio strategies of the portfolio insurers and normal agents at a general equilibrium level comparisons across economies reveal that the market volatility and risk premium are decreased and the asset and market price levels increased by the presence of portfolio insurance article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

food stamps and food insecurity what can be learned in the presence of nonclassical measurement error policymakers have been puzzled to observe that food stamp households appear more likely to be food insecure than observationally similar eligible nonparticipating households we reexamine this issue allowing for nonclassical reporting errors in food stamp participation and food insecurity extending the literature on partially identified parameters we introduce a nonparametric framework that makes transparent what can be known about conditional probabilities when a binary outcome and conditioning variable are both subject to nonclassical measurement error we find that the food insecurity paradox hinges on assumptions about the data that are not supported by the previous food stamp participation literature

belief disagreements and collateral constraints belief disagreements have been suggested as a major contributing factor to the recent subprime mortgage crisis this paper theoretically evaluates this hypothesis i assume that optimists have limited wealth and take on leverage so as to take positions in line with their beliefs to have a significant effect on asset prices they need to borrow from traders with pessimistic beliefs using loans collateralized by the asset itself since pessimists do not value the collateral as much as optimists do they are reluctant to lend which provides an endogenous constraint on optimists ability to borrow and to influence asset prices i demonstrate that the tightness of this constraint depends on the nature of belief disagreements optimism concerning the probability of downside states has no or little effect on asset prices because these types of optimism are disciplined by this constraint instead optimism concerning the relative probability of upside states could have significant effects on asset prices this asymmetric disciplining effect is robust to allowing for short selling because pessimists that borrow the asset face a similar endogenous constraint these results emphasize that what investors disagree about matters for asset prices to a greater extent than the level of disagreements when richer contracts are available relatively complex contracts that resemble some of the recent financial innovations in the mortgage market endogenously emerge to facilitate betting

dynamic equilibrium with liquidity constraints this article studies an intertemporal economy with liquidity constrained and unconstrained individuals we use a stopping time approach to solve the finite horizonconstrained consumption portfolio problem with constant relative risk aversion and to examine the structure of equilibrium the impact of the constraint on the optimal consumption and the financing portfolio is assessed the equilibrium state price density is related to the exercise boundary of an american style contingent claim with nonlinear payoff this stopping time characterization enables us to prove the existence of an equilibrium and can be implemented numerically properties of equilibrium bond and stock returns are examined copyright 2003 oxford university press

asset pricing with heterogeneous preferences beliefs and portfolio constraints portfolio constraints are widespread and have significant effects on asset prices this paper studies the effects of constraints in a dynamic economy populated by investors with different risk aversions and beliefs about the rate of economic growth the paper provides a comparison of various constraints and conditions under which these constraints help match certain empirical facts about asset prices under these conditions borrowing and short sale constraints decrease stock return volatilities whereas limited stock market participation constraints amplify them moreover borrowing constraints generate spikes in interest rates and volatilities and have stronger effects on asset prices than short sale constraints

leverage cycles and the anxious economy ing opportunities for emerging economies their access to international markets has turned out to be very volatile with frequent periods of market closures even worse as we will show emerging economies with sound fundamentals are the ones that issue less debt during these closures the goal of this paper is to present a theory of asset pricing that will shed light on the problems of emerging assets like emerging markets that are not yet mature enough to be attractive to the general public their marginal buyers are liquidity constrained investors with small wealth relative to the whole economy who are also marginal buyers of other risky assets we will use our theory to argue that the periodic problems faced by emerging asset classes are sometimes symptoms of what we call a global anxious economy rather than of their own fundamental weaknesses

the role of portfolio constraints in the international propagation of shocks we study the comovement among stock prices and exchange rates in a three good three country centre periphery dynamic equilibrium model in which the centre s agents face portfolio constraints we characterize equilibrium in closed form for a broad class of portfolio constraints solving for stock prices terms of trade and portfolio holdings we show that portfolio constraints generate wealth transfers between the periphery countries and the centre which increase the comovement of the stock prices across the periphery we associate this excess comovement caused by portfolio constraints with the phenomenon known as contagion the model generates predictions consistent with other important empirical results such as amplification and flight to quality effects copyright 2008 wiley blackwell

in kind benefits and household behavior the impact of snap on food away from home consumption abstract supplemental nutrition assistance program snap formerly known as the food stamp program provides in kind benefits that can generally be utilized for food at home fah only according to economic theory snap benefits are fungible with cash for inframarginal households which may allow participants to spend benefits on non fah items however empirical evidence for this theory is mixed this paper exploits an underutilized source of state level variation the early 2000 s recession to determine the impact of snap participation on household food away from home fafh consumption in a difference in difference framework i compare households in high post recession snap growth states to households in low post recession snap growth states the results show that snap participation causes a significant decrease in fafh expenditure and fafh s share of total food expenditure

a theoretical and empirical evaluation of the functional forms used to estimate the food expenditure equation of food stamp recipients the food expenditure equation of food stamp recipients is obtained as a generalization of roy s identity this equation rationalizes a larger marginal propensity to spend on food out of food stamps than out of income and is an alternative to the traditional southworth formulation the only previously estimated functional form found to be flexible is due to senauer and young estimates of this specification using data from the san diego cash out demonstration illustrates that flexibility is important an example of welfare reform demonstrates that substantial errors can occur if flexibility is ignored

a macroeconomic model with a financial sector this paper studies a macroeconomic model in which financial experts borrow from less productive agents we pursue four sets of results i the economy is prone to instability and occasionally enters volatile episodes as volatility spikes agents precautionary motive increases depressing prices even further log linear approximations fail to capture these non linear effects that can cause economies to be significantly depressed for long periods of time ii endogenous risk during volatile episodes increases asset price correlations iii financial experts impose a negative externality on each other and on the labor sector by not maintaining adequate capital cushion and funding structure iv while risk sharing within the financial sector through securitization and derivatives contracts reduces many inefficiencies it can also amlify systemic risks

are two cheap noisy measures better than one expensive accurate one 1 survey responses are always subject to measurement error in general surveys and especially longitudinal surveys there are severe constraints on the time that can be spent eliciting a less noisy response for any target variable in this paper we consider when it may be better to consider multiple noisy measures of the target measure rather than improving the reliability of a single measure 2 the kotlarski result states that if the measurement errors in two measures of the same target variable are mutually independent and independent of the true value then we can recover the entire distribution of the quantity of interest up to location 3 we consider designing surveys to deliver measurement error with desirable properties this shifts the emphasis from reliability the signal to noise ratio for any given measure to the joint properties of the multiple measures 4 to illustrate our ideas we consider a concrete example the measurement of consumption inequality a small simulation study suggests that the approach we propose has promise the next step in this research agenda is experiments in survey data collection

do intra household effects generate the food stamp cash out puzzle previous empirical studies have noted the higher marginal propensity to consume food out of food stamps in the united states compared to that out of cash income analyzing data from u s food stamp program participants we find evidence that this discrepancy may be driven primarily by the behavior of multiple adult households single adult households show no evidence of any discrepancy thus our results suggest that food stamp and cash income welfare or market may have very different impact on the intra household allocation process and that this is reflected empirically in the cash out puzzle

the credibility revolution in empirical economics how better research design is taking the con out of econometrics since edward leamer s memorable 1983 paper let s take the con out of econometrics empirical microeconomics has experienced a credibility revolution while leamer s suggested remedy sensitivity analysis has played a role in this we argue that the primary engine driving improvement has been a focus on the quality of empirical research designs the advantages of a good research design are perhaps most easily apparent in research using random assignment we begin with an overview of leamer s 1983 critique and his proposed remedies we then turn to the key factors we see contributing to improved empirical work including the availability of more and better data along with advances in theoretical econometric understanding but especially the fact that research design has moved front and center in much of empirical micro we offer a brief digression into macroeconomics and industrial organization where progress by our lights is less dramatic although there is work in both fields that we find encouraging finally we discuss the view that the design pendulum has swung too far critics of design driven studies argue that in pursuit of clean and credible research designs researchers seek good answers instead of good questions we briefly respond to this concern which worries us little

expenditure response to increases in in kind transfers evidence from the supplemental nutrition assistance program recent studies on food stamp participant households marginal propensity to spend out of food stamps versus income have had contradictory results experimental studies have found household behavior aligns with standard economic theory where households marginal propensity to spend on food out of food stamps is equivalent to cash income observational studies nd that households have a larger marginal propensity to spend out of food stamps than cash income in this study we re examine this question by estimating how an unprecedentedly large increase in food stamp benets due to the implementation of the american recovery and reinvestment act aects food at home expenditure we nd that the policy change caused households to increase food at home expenditure as well as increase households share of total expenditure allocated toward food at home expenditure we compare these results to a time period without a meaningful food stamp policy change and nd our results are unique to the arra implementation time period

saving and liquidity constraints this paper is concerned with the theory of saving when consumers are not permitted to borrow and with the ability of such a theory to account for some of the stylized facts of saving behavior the models presented in the paper seem to account for important aspects of reality that are not explained by traditional life cycle models copyright 1991 by the econometric society

the dynamics of financially constrained arbitrage we develop a model of financially constrained arbitrage and use it to study the dynamics of arbitrage capital liquidity and asset prices arbitrageurs exploit price discrepancies between assets traded in segmented markets and in doing so provide liquidity to investors a collateral constraint limits their positions as a function of capital we show that the dynamics of arbitrage activity are self correcting following a shock that depletes arbitrage capital profitability increases and this allows capital to be gradually replenished spreads increase more and recover faster for more volatile trades although arbitrageurs cut their positions in these trades the least when arbitrage capital is more mobile across markets liquidity in each market generally becomes less volatile but the reverse may hold for aggregate liquidity because of mobility induced contagion

a case for incomplete markets we propose a new welfare criterion that allows us to rank alternative financial market structures in the presence of belief heterogeneity we analyze economies with complete and incomplete financial markets and or restricted trading possibilities in the form of borrowing limits or transaction costs we describe circumstances under which various restrictions on financial markets are desirable according to our welfare criterion

estimating the value of an in kind transfer the case of food stamps the value of one in kind transfer food stamps is estimated by evaluating the experience of an actual conversion from stamps to cash in puerto rico in 1982 the evidence indicates that the cashout of the stamps had no detectable influence on food expenditures the explanation partly lies in the distribution of expenditures for the stamps were inframarginal for most recipients however some evidence indicates that trafficking in stamps was widespread as well including indirect evidence from estimation of the piecewise linear constraint model copyright 1989 by the econometric society

intertemporal choice and income regularity non fungibility in the timing of income among kenyan farmers the optimal design of informal contracts in agricultural value chains depends on when farmers prefer to be paid for their output while the evidence from time preference experiments suggests a pref

who benefits from child benefit governments over much of the developed world make significant financial transfers to parents with dependent children for example in the united states the recently introduced child tax credit ctc which goes to almost all children costs almost 1 billion each week or about 0 4 of gnp the united kingdom has even more generous transfers and spends an average of about 30 a week on each of about 8 million children about 1 of gnp the typical rationale given for these transfers is that they are good for our children and here we investigate the effect of such transfers on household spending patterns in the united kingdom such transfers known as child benefit cb have been simple lump sum universal payments for a continuous period of more than 20 years we do indeed find that cb is spent differently from other income paradoxically it appears to be spent disproportionately on adult assignable goods in fact we estimate that as much as half of a marginal dollar of cb is spent on alcohol we resolve this puzzle by showing that the effect is confined to unanticipated variation in cb so we infer that parents are sufficiently altruistic toward their children that they completely insure them against shocks

how are snap benefits spent evidence from a retail panel we use a novel retail panel with more than six years of detailed transaction records to study the effect of participation in the supplemental nutrition assistance program snap on household spending we frame our approach using novel administrative data from the state of rhode island the marginal propensity to consume snap eligible food mpcf out of snap benefits is 0 5 to 0 6 the mpcf out of cash is much smaller these patterns obtain even for households for whom snap benefits are economically equivalent to cash in the sense that benefits do not cover all food spending we reject the hypothesis that households respect the fungibility of money in a semiparametric framework a model with mental accounting can match the facts

an experiment on cash and in kind transfers with application to food assistance programs the impact of providing food assistance in kind via food stamps or restricted debit cards vs cash has long been a subject of debate prior efforts to causally identify the effects of the two types of transfers have been hindered by concerns over non random selection into assistance programs misreporting of program benefits and identification of inframarginal households who theoretically should treat cash and in kind transfers identically this paper reports the results of an economic experiment designed to cleanly test some conceptual issues associated with in kind vs cash giving in a lunchroom meal setting given current debates about the healthiness of food assistance recipients diets we also consider the impacts of placing restrictions on in kind transfers that either prohibit soda purchases with the transfer or require the transfer be spent on fruits and vegetables overall we find that as theory predicts in kind transfers have the same effect on food expenditures as an unrestricted cash transfer for inframarginal consumers and for extramarginal consumers food expenditures are higher for in kind than cash transfers participants also respond to the fruit and vegetable restriction as theory would predict however in contrast to the theoretical prediction the soda restriction reduces soda expenditures for more than half the inframarginal consumers

the behavioral relevance of mental accounting for the pricing of financial options abstract the paper reports an experiment on the pricing of financial options arbitrage free option pricing is tested against three hypotheses based on mental accounting the data show that even with considerable experience unexploited arbitrage opportunities persist subjects do not seem to make the connections between the different investment possibilities as essential for arbitrage free pricing afp instead they act as if they associate the risky assets to the same mental account while the bond is treated separately this corresponds to the construction of a two layer portfolio of a risky and a safe layer in the behavioral portfolio theory of shefrin and statman j fin quant anal 35 2000 127

dynamic equilibrium with two stocks heterogeneous investors and portfolio constraints we study dynamic equilibrium in a lucas economy with two stocks two heterogeneous constant relative risk aversion investors and portfolio constraints we focus on margin and leverage constraints which restrict access to credit we find a positive relationship between the amount of leverage in the economy and magnitudes of stock return correlations and volatilities tighter constraints generate rich patterns in correlations and volatilities make them less countercyclical increase risk premia proportionally to assets margins and increase prices of low margin assets more than prices of high margin assets we derive closed form solutions for the unconstrained case and the case of leverage constraints

income and wealth heterogeneity in the macroeconomy how do movements in the distribution of income and wealth affect the macroeconomy we analyze this question using a calibrated version of the stochastic growth model with partially uninsurable idiosyncratic risk and movements in aggregate productivity our main finding is that in the stationary stochastic equilibrium the behavior of the macroeconomic aggregates can be almost perfectly described using only the mean of the wealth distribution this result is robust to substantial changes in both parameter values and model specification our benchmark model whose only difference from the representative agent framework is the existence of uninsurable idiosyncratic risk displays far less cross sectional dispersion and skewness in wealth than u s data however an extension that relies on a small amount of heterogeneity in thrift does succeed in replicating the key features of the wealth data furthermore this extension features aggregate time series that depart significantly from permanent income behavior

an analysis of the impact of sample attrition on the second generation of respondents in the michigan panel study of income dynamics only a few studies have tried to estimate the trend in the elasticity of children s economic status with respect to parents economic status and these studies produce conflicting results in an attempt to reconcile these findings we use the panel study

do snap participants expand non food spending when they receive more snap benefits evidence from the 2009 snap benefits increase this study examines the expenditure response to the largest increase in supplemental nutrition assistance program benefits instituted in april 2009 investigating the effects in both food and non food spending categories i find that the rise in snap benefits increased not only food at home expenditures but also housing transportation and education expenditures of snap households relative to those of non snap households specifically the snap benefit increase leads to the reduced out of pocket spending on food for infra marginal snap recipients and the freed up resources allowed households with bounded budgets to fund other essential needs such as paying mortgage rent utility fee transportation expenses as well as tuition examining non food expenditures provides a more complete picture of the impact of the snap benefit increase by shedding light on the spillover effect of the policy change the result also derives policy implication on ongoing debate about snap allotment generosity

collateral constraints and asset prices abstract we study the effects of collateral constraints in an economy populated by investors with nonpledgeable labor incomes and heterogeneous preferences and beliefs we show that these constraints inflate stock prices and generate spikes and crashes in price dividend ratios and volatilities clustering of volatilities and leverage cycles they also lead to substantial decreases in interest rates and increases in sharpe ratios when investors are anxious about hitting constraints due to production crises in the economy furthermore stock prices have large collateral premiums over nonpledgeable incomes we derive asset prices and stationary distributions of the investors consumption shares in closed form

belief dispersion in the stock market we develop a dynamic model of belief dispersion with a continuum of investors differing in beliefs the model is tractable and qualitatively matches many of the empirical regularities in a stock price its mean return volatility and trading volume we find that the stock price is convex in cash flow news and increases in belief dispersion while its mean return decreases when the view on the stock is optimistic and vice versa when pessimistic moreover belief dispersion leads to a higher stock volatility and trading volume we demonstrate that otherwise identical two investor heterogeneous beliefs economies do not necessarily generate our main results

differences of opinion endogenous liquidity and asset prices this paper studies how investors differences of opinion affect liquidity and asset prices in our economy excessively optimistic investors are subject to an endogenous funding constraint that prevents default due to ex ante limited commitment when the funding constraint binds optimists use their savings to increase their consumption share deterring default this allows them to place speculative trades increasing market liquidity their losses on these trades make them prone to default leading to a renewed binding of the funding constraint this feedback between funding illiquidity disagreement and market liquidity is consistent with several empirical features of liquidity and financial asset prices

survival and long run dynamics with heterogeneous beliefs under recursive preferences i analytically characterize the long run behavior of an economy with two types of agents who differ in their beliefs and are endowed with homothetic recursive preferences agents with more incorrec

the monthly food stamp cycle shooping frequency and food intake decisions in an endogenous switching regression framework mean food spending by food stamp households peaks sharply in the first three days after benefits are received for those who conduct major grocery shopping trips only once per month 42 of all food stamp households mean food energy intake drops significantly by the fourth week of the month for the remaining households intake remains steady over the course of the month these patterns motivate an empirical model that simultaneously accounts for the shopping frequency and food intake decisions over time results have implications for policies that may affect the frequency of grocery shopping by food stamp households

food stamps and food spending an engel function approach estimation of food stamp program fsp effects has been complicated by self selection and by a contradiction between observed spending patterns and the economic theory of consumer choice we developed a modified version of the traditional theory in which participant households may be partly extramarginal even if they have some cash spending on at home food using current population survey cps data for 2001 2005 we estimated engel functions for at home and away from home food spending for fsp participants and nonparticipants compared to nonparticipants with the same level of total income participants had higher at home food spending and lower away from home food spending copyright 2007 oxford university press

margin based asset pricing and deviations from the law of one price in a model with heterogeneous risk aversion agents facing margin constraints we show how securities required returns increase in both their betas and their margin requirements negative shocks to fundamentals make margin constraints bind lowering risk free rates and raising sharpe ratios of risky securities especially for high margin securities such a funding liquidity crisis gives rise to bases that is price gaps between securities with identical cash flows but different margins in the time series bases depend on the shadow cost of capital which can be captured through the interest rate spread between collateralized and uncollateralized loans and in the cross section they depend on relative margins we test the model empirically using the credit default swap bond bases and other deviations from the law of one price and use it to evaluate central banks lending facilities jel g01 g12 g13 e44 e50 the paramount role of funding constraints becomes particularly salient during liquidity crises with the one that started in 2007 being an excellent case in point banks unable to fund their operations closed down and the funding problems spread to other investors such as hedge funds that relied on bank funding therefore traditional liquidity providers became forced sellers interest rate spreads increased dramatically treasury rates dropped sharply and central banks stretched their balance sheets to facilitate funding these funding problems had significant asset pricing effects the most extreme example being the failure of the law of one price loop securities with nearly

the intended and unintended consequences of financial market regulations a general equilibrium analysis in a production economy with trade in financial markets motivated by the desire to share labor income risk and to speculate we show that speculation increases volatility of asset returns and investment growth increases the equity risk premium and reduces welfare regulatory measures such as constraints on stock positions borrowing constraints and the tobin tax have similar effects on financial and macroeconomic variables borrowing limits and a financial transaction tax improve welfare because they substantially reduce speculative trading without impairing excessively risk sharing trades

the labeling effect of a child benefit system child benefit systems exist in many countries while they show a lot of differences in terms of eligibility rules amounts involved and implementation tax deduction tax credit or direct benefit the common motivation for their existence is to increase children s welfare in the dutch child benefit system the case i focus on in this paperone of the parents usually the mother is entitled to an untaxed child benefit amount which only depends on the child s age and the number of children in the household thus child support does not depend on household income marital status or labor market status as a result child benefit is exogenous to the household given the presence of children this is in contrast with the situation in many other countries including germany france the united kingdom and the united states where government provided child support is partly means tested see jonathan bradshaw et al 1993 in the netherlands child benefit is generally a nonnegligible addition to the household income the median share of child benefit in the total net income of households with children is 8 percent on the national level expenditures on child benefits amount to 1 2 percent of gnp the use of the child benefit is completely at the discretion of the parent there are no legal requirements that a certain amount be spent on particular goods or services nor does the government provide any guidelines regarding expenditure on children a policy question that arises is to what extent children benefit from child benefits standard microeconomic demand theory allows no role for effects of the composition of income given the fungibility of income sources it is only the sum of income components that is relevant in explaining expenditure patterns thus within that framework the answer would be that the marginal propensity to consume child goods from one guilder of child benefits is no different than from one guilder of any other income source in the more general class of gametheoretic models of household behavior however the composition of household income will generally affect expenditure patterns see e g shelly j lundberg and robert a pollak 1993 and martin browning et al 1994 if fathers and mothers have different preferences and mothers have control over child benefits the effect of child benefits on expenditures will differ from the effect of other income sources lundberg et al 1997 provide empirical evidence showing that a transfer of control over child benefits from fathers to mothers in the united kingdom due to a change in legislation resulted in a significant increase in expenditures on child clothing daniela del boca and christopher j flinn 1994 have analyzed the effect of income composition on expenditure decisions of divorced mothers they find that the coefficients associated with child support and alimony income differ from those for other income in engel curves for expenditures on childspecific goods their results can be explained in terms of a noncooperative nash model in which the child support transfer decisions of the noncustodial father and the expenditure decisions of the mother are determined simultaneously in contrast to del boca and flinn s analysis in which child support is a decision variable the present paper focuses on the possible differential effect of government provided child support which is truly exogenous in this paper i analyze the effects of child benefits on expenditures by running regressions in which child benefit enters as a separate explanatory variable the enipirical analysis is based on a time series of 17 cross section consumer expenditure surveys in the netherlands covering the period 1978 through 1994 it is important to note that in a single cross section it department of economics university of groningen p o b 800 9700 av groningen the netherlands e mail p kooreman eco rug nl i am indebted to two anonymous referees for constructive comments helpful comments were also provided by rob alessie maarten allers chris bojke werner de bondt bert schoonbeek and tom wansbeek i thank vincent linderhof for organizing the data financial support was provided by the dutch organization for scientific research nwo homes project grant

stationary equilibria in asset pricing models with incomplete markets and collateral we consider an infinite horizon exchange economy with incomplete markets and collateral constraints as in the two period model of geanakoplos and zame 2002 households can default on their liabilities at any time and financial securities are only traded if the promises associated with these securities are backed by collateral we examine an economy with a single perishable consumption good where the only collateral available consists of productive assets in this model competitive equilibria always exist and we show that under the assumption that all exogenous variables follow a markov chain there also exist stationary equilibria these equilibria can be characterized by a mapping from the exogenous shock and the current distribution of financial wealth to prices and portfolio choices we develop an algorithm to approximate this mapping numerically and discuss ways to implement the algorithm in practice a computational example demonstrates the performance of the algorithm and shows some quantitative features of equilibria in a model with collateral and default

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

frugality is hard to afford intertemporal savings strategies such as bulk buying or accelerating purchase timing to take advantage of a good deal provide long term savings in exchange for an increase in immediate spending

the impact of food stamps on food expenditures rejection of the traditional model for food stamp recipients whose normal food purchases exceed their coupon allotment the traditional economic model predicts that the impact of food stamps on food spending will be the same as for an equal cash transfer the tobit analysis in this study indicates that for these recipients food stamps have a substantially greater impact on at home food expenditures than an equal amount of cash income these results reject the traditional model several possible explanations of this behavior are discussed

margin regulation and volatility an infinite horizon asset pricing model with heterogeneous agents and collateral constraints can explain why adjustments in stock market margins under us regulation t had an economically insignificant impact on market volatility in the model raising the margin requirement for one asset class may barely affect its volatility if investors have access to another unregulated class of collateralizable assets through spillovers however the volatility of the other asset class may substantially decrease a very strong dampening effect on all assets return volatilities can be achieved by a countercyclical regulation of all markets