statistical equilibrium wealth distributions in an exchange economy with stochastic preferences abstract we describe an exchange market consisting of many agents with stochastic preferences for two goods when individuals are indifferent between goods statistical mechanics predicts that goods and wealth will have steady state gamma distributions simulation studies show that gamma distributions arise for a broader class of preference distributions we demonstrate this mathematically in the limit of large numbers of individual agents these studies illustrate the potential power of a statistical mechanical approach to stochastic models in economics and suggest that gamma distributions will describe steady state wealths for a class of stochastic models with periodic redistribution of conserved quantities journal of economic literature classification numbers c15 c62 c73 d3 d5

economic shocks wealth and welfare the immediate effects of the asian crisis on the well being of indonesians are examined using the indonesia family life survey an on going longitudinal household survey there is tremendous diversity in the effect of the shock for some households it was devastating for others it brought new opportunities a wide array of mechanisms were adopted in response to the crisis households combined to more fully exploit benefits of scale economies in consumption labor supply increased even as real wages collapsed households reduced spending on semi durables while maintaining expenditures on foods rural households used wealth particularly gold to smooth consumption

credit market constraints consumption smoothing and the accumulation of durable production assets in low income countries investments in bullocks in india in this paper we formulate and estimate a finite horizon structural dynamic model of agricultural investment behavior that incorporates the major features of low income agricultural environments income uncertainty constraints on borrowing and rental markets and the use of investment assets to generate income and smooth consumption the model is fit to longitudinal indian household data on farm profits bullock stocks and pump sets the estimated structural parameters are used to assess the effects on the life cycle accumulation of bullocks agricultural profits and welfare associated with complete markets and bullock liquidity and with second best policies that provide assured sources of income to farmers and weather insurance

the behavior of prices and inflation an empirical analysis of disaggregat price data this paper analyzes the effects of inflation on the dispersion of prices as well as other aspects of price behavior using disaggregated data on prices of foodstuffs in israel during 1978 84 we find that the effect of expected inflation on intramarket price variability is stronger than the effect of unexpected inflation we show that even in times of high inflation price quotations are not trivially short and price changes are not synchronized across firms these facts taken together confirm that there is some staggering in the setting of prices we find that the distribution of real prices is far from being uniform as many menu cost based models assume or conclude in fact as inflation increases to very high levels this distribution is not even symmetric when the annual inflation rate reaches 130 percent there are equal chances of finding real prices above or below the market average but upward deviations in the real price are further away from zero than downward ones furthermore as the annu

buying less but shopping more the use of nonmarket labor during a crisis households allocating time between market and non market uses should respond to income variations by adjusting the time devoted to shopping search and other home production activities in this paper we exploit high frequency household expenditure data to examine the use of changes in shopping intensity as a method of mitigating the effects of the 2002 argentine economic crisis although the total quantity and real value of goods purchased fell during the crisis consumers are found to be doing more shopping search this increase in shopping is shown to enable households to seek out lower prices and locate substitutes allowing a given level of expenditure to buy more goods the magnitude and prevalence of these effects suggest that this non market use of labor can be an important coping strategy for households during a recession

exploiting ergodicity in forecasts of corporate profitability abstract theory suggests that competition tends to equalize profit rates through the process of capital reallocation and numerous studies have confirmed that profit rates are indeed persistent and mean reverting recent empirical evidence further shows that fluctuations in the profitability of surviving corporations are well approximated by a stationary laplace distribution here we show that a parsimonious diffusion process of corporate profitability that accounts for all three features of the data achieves better out of sample forecasting performance across different time horizons than previously suggested time series and cross sectional models as a consequence of replicating the empirical distribution of profit rates the model prescribes a particular strength or speed for the mean reversion of all returns which leads to superior forecasts of individual time series when we exploit information from the cross sectional collection of firms the new model should appeal to managers analysts investors and other groups of corporate stakeholders who are interested in accurate forecasts of profitability to the extent that mean reversion in profitability is the source of predictable variation in earnings our approach can also be used in forecasts of earnings and is thus useful for firm valuation

a statistical equilibrium model of competitive firms abstract we find that the empirical density of firm profit rates measured as returns on assets is markedly non gaussian and reasonably well described by an exponential power or subbotin distribution we start from a statistical equilibrium model that leads to a stationary subbotin density in the presence of complex interactions among competitive heterogeneous firms to investigate the dynamics of firm profitability we construct a diffusion process that has the subbotin distribution as its stationary probability density this leads to a phenomenologically inspired interpretation of variations in the shape parameter of the subbotin distribution which essentially measures the competitive pressure in and across industries our findings have profound implications both for the previous literature on the persistence of profits as well as for understanding competition as a dynamic process our main formal finding is that firms idiosyncratic efforts and the tendency for competition to equalize profit rates are two sides of the same coin and that a ratio of these two effects ultimately determines the dispersion of the equilibrium distribution

living and dying with hard pegs the rise and fall of argentina s currency board the rise and fall of argentina s currency board shows the extent to which the advantages of hard pegs have been overstated the currency board did provide nominal stability and boosted financial intermediation at the cost of endogenous financial dollarization but did not foster monetary or fiscal discipline the failure to adequately address the currency growth debt trap into which argentina fell at the end of the 1990s precipitated a run on the currency and the banks followed by the abandonment of the currency board and a sovereign debt default the crisis can be best interpreted as a bad outcome of a high stakes strategy to overcome a weak currency problem to increase the credibility of the hard peg the government raised its exit costs which deepened the crisis once exit could no longer be avoided but some alternative exit strategies would have been less destructive than the one adopted

immigration and prices this paper examines the behavior of prices following the unexpected arrival of a large number of immigrants from the former soviet union fsu to israel during 1990 i use store level price data on 915 consumer price index products to show that the increase in aggregate demand prompted by the arrival of the fsu immigration significantly reduced prices during 1990 when one controls for native population size and city and month effects a one percentage point increase in the ratio of immigrants to natives in a city decreases prices by 0 5 percentage point on average it is argued that this negative immigration effect is consistent with fsu immigrants the new consumers having higher price elasticities and lower search costs than the native population thus immigration can have a moderating effect on inflation through its direct effect on product markets and not only by increasing the supply of labor

on high inflation and the allocation of resources abstract this paper formalizes some of the disruptive effects of inflation on the organization of markets rapid inflation induces buyers to speed up purchases which thus inhibits the selection of more adequate trading partners through search this blurs distinctions across firms of different productivities and leads to resource misallocations as inflation causes efficient and inefficient firms to be less distinguishable the incentives to engage in cost reduction are dampened and lower growth results the model could provide a rationale for the large number of bankruptcies and large turnover rates following successful inflation stabilization programs like those of israel bolivia and argentina

the timing and magnitude of retail store markdowns evidence from weekends and holidays we examine daily prices of eight goods at seventeen retail stores collected in ann arbor michigan over a four month period from november 1 to february 28 we focus on weekly and seasonal price patterns and on the frequency of price markdowns or sales there were frequent markdowns in the intensive shopping period prior to christmas and a tendency for such sales to occur on weekends we interpret these findings as evidence that a significant number of markdowns are timed to occur when shopping intensity is exogenously high we complement the imperfect information based motives for sales in the literature by contributing an additional element based on the role of bulk shopping and increasing returns in the shopping technology

search sticky prices and inflation this paper examines equilibrium in a deflationary environment in a market with free entry where consumers search and firms set prices on individual units of the commodity prices attached to newly produced goods are continuously adjusted prices attached to previously produced goods can only be changed at a cost deflation cuts into the market power created by the need to search for the good thus consumers welfare is inverse u shaped in deflation

risk and insurance in a rural credit market an empirical investigation in northern nigeria credit contracts play a direct role in pooling risk between households in northern nigeria repayments owed by borrowers depend on realizations of random shocks by both borrowers and lenders the paper develops two models of state contingent loans the first is a competitive equilibrium in perfectly enforceable contracts the second permits imperfect information and equilibrium default estimates of both models indicate that quantitatively important state contingent payments are embedded in these loan transactions but that a fully efficient risk pooling equilibrium is not achieved the research is based on a year long survey in zaria nigeria conducted by the author

household production and the excess sensitivity of consumption to current income empirical research on the permanent income hypothesis pih has found that consumption growth is excessively sensitive to predictable changes in income this finding is interpreted as strong evidence against the pih we propose an explanation for apparent excess sensitivity that is based on a quantitative equilibrium model of household production in which permanent income consumers respond to shifts in sectoral wages and prices by substituting work effort and consumption across home and market sectors although the pih is true this mechanism generates apparent excess sensitivity because market consumption responds to predictable income growth

price dispersion and inflation evidence from israel the paper considers the question whether observed price differentials reflect perceived differences in quality service agreements or location or whether information imperfections can explain this phenomenon it sets out theoretical arguments linking inflation to reductions in the information stock held by agents and thus to greater price dispersion the hypothesis is tested using monthly price data for 13 uniquely defined goods sold in israel between 1971 and 1984 price dispersion is shown to be positively related to the rate of market price inflation since inflation is an unlikely proxy for changes in perceived characteristics the findings support price dispersion theories based on optimally imperfect decision making

the elasticity of substitution between time and market goods evidence from the great recession the elasticity of substitution between time and market goods we document a change in household shopping behavior during the great recession households purchased more on sale larger sizes and generic products increased coupon usage and shopping at discount stores we estimate that the returns to these shopping activities declined during the recession and therefore this behavior implies a significant decrease in households opportunity cost of time using the estimated cost of time and time use data we estimate a high elasticity of substitution between market expenditure and time spent on non market work we find that households smooth a sizable fraction of consumption by varying their time allocation during recessions institutional subscribers to the nber working paper series and residents of developing countries may download this paper without additional charge at www nber org

crises and the poor socially responsible macroeconomics this paper presents evidence on the impact of economic crisis on poverty and inequality in latin america crises not only result in higher poverty rates but also may cause irreversible damage to the human capital of the poor in light of this evidence the author concludes that crisis avoidance and a pro poor response to crisis should be a major component of a poverty reduction strategy as a result the paper analyses the role of exchange rate policy capital controls and countercyclical fiscal policy in generating or avoiding crisis responses to macroeconomic crisis are assessed by considering the effects of different policy combinations the use of safety nets and the composition of fiscal adjustment to protect the income of the poor in the face of macroeconomic adjustment the main lesson is that socially responsible macroeconomic policy can protect the poor during times of crisis and simultaneously contribute to lower chronic poverty

income smoothing and consumption smoothing one way that risk averse households protect consumption levels is to borrow and use insurance mechanisms another way common in low income economies is to diversify economic activities and make conservative production and employment choices households thus tend toward limiting exposure only to shocks that can be handled with available credit and insurance typically both types of mechanisms are studied independently but much more can be learned by studying them together first we obtain a more complete picture of risks costs and insurance possibilities second it opens the way to considering biases in standard tests of credit and insurance

economic exchange during hyperinflation historical evidence indicates that hyperinflations can disrupt individuals normal trading patterns and impede the orderly functioning of markets to explore these issues we construct a theoretical model of hyperinflation that focuses on individuals and their process of economic exchange in our model buyers must carry cash while shopping and some transactions take place in a decentralized setting in which buyer and seller negotiate over the terms of trade of an indivisible good since buyers face the constant threat of incoming younger hence richer customers their bargaining position is weakened by inflation allowing sellers to extract a higher real price however we show that higher inflation also reduces buyers search increasing sellers wait for customers as a result the volume of transactions concluded in the decentralized sector falls at high enough rates of inflation all agents suffer a welfare loss

homework in development economics household production and the wealth of nations we introduce home production into the neoclassical growth model and examine its consequences for development economics in particular we study the extent to which one can account for international income differences with differences in policies that distort capital accumulation in models with home production such policies not only reduce capital accumulation but also change the mix of market and nonmarket activity hence these models can generate larger differences in output than standard models for a given policy differential we also show how the welfare implications change when we incorporate home production

trade liberalization and regional dynamics abstract we study the evolution of trade liberalization s effects on brazilian local labor markets regions facing larger tariff cuts experienced prolonged declines in formal sector employment and

explaining the distribution of firm growth rates empirical analyses on aggregated datasets have revealed a common exponential behavior in the shape of the probability density of corporate growth rates we present clear cut evidence on this topic using disaggregated data we explain the observed regularities proposing a model in which firms ability to take up new business opportunities increases with the number of opportunities already exploited a theoretical result is presented for the limiting case in which the number of firms and opportunities go to infinity moreover using simulations we show that even in a small industry the agreement with asymptotic results is almost complete

sticky prices new evidence from retail catalogs this paper presents new results on the size frequency and synchronization of price changes for twelve selected retail goods over the past 35 years three basic facts about the data are uncovered first nominal prices are typically fixed for more than one year although the time between changes is very irregular second prices change more often during periods of high overall inflation third when prices do change the sizes of the changes are widely dispersed both large and small changes occur for the same item and the sizes of these changes do not closely depend on overall inflation

explaining cross country productivity differences in retail trade many macroeconomists argue that productivity is low in developing countries because of frictions that impede the adoption of modern technologies i argue that in the retail trade sector developing countries rationally choose technologies with low measured labor productivity my theory is that the adoption of modern retail technologies is optimal only when household ownership of complementary durable goods such as cars is widespread because income is low in the developing world households own few such durables the theory implies that policies that increase measured retail productivity do not necessarily increase welfare

why does consumption fall at retirement evidence from germany abstract analyzing the consumption behavior over retirement in germany this paper finds a negative correlation between income replacement and the increase in home production related activities this might reconcile the observed drop in consumption at retirement with the predictions of the standard life cycle model however since individuals with fairly stable income over retirement also increase home production this increase cannot be entirely attributed to a substitution effect

mechanization in ghana emerging demand and the search for alternative supply models influential studies in the 1980s and early 1990s drew on the boserup ruthenberg theories of farming systems evolution to argue that african countries were not yet ready for widespread agricultural mechanization through applying the theories of farming systems evolution and of induced innovation in technical change this paper shows that demand for certain mechanized farming operations particularly plowing has emerged even among smallholders suggesting that supply issues may now be the main constraint to successful mechanization we therefore adopt a supply chain approach to analyze two types of mechanization practices in ghana i e a recent state led mechanization program and the private sector led service hiring market against an international perspective by drawing on three asian supply models we identify two major flaws in existing policies first the agricultural mechanization service centers that the government promotes fail to use tractors services with sufficient intensity second direct importation of agricultural machinery by the government inhibits imports of appropriate and affordable machinery in contrast the development of mechanized service hiring market in which medium and large scale farmers who are tractor owners provide hiring out services to small scale farmers represents a promising model for sustainable mechanization in ghana this private sector led second model is consistent with international experiences

great expectations and hard times the argentine convertibility plan this paper studies the process that led to the argentine crisis the analysis concentrates on the sequence of public and private decisions together with the varying perceptions and policy incentives that motivated them in the 1990s argentina searched for a new growth trend during much of the period the behavior of agents seemed to be based on the anticipation that current and future incomes could sustain a value of domestic spending much higher than in the past in both real and dollar terms the government was motivated to reinforce those expectations for signaling and political economy reasons the monetary regime not only provided a very visible nominal anchor but also operated as a basic framework for financial contracts mostly denominated in dollars dollar contracting implicitly presumed that the dollar value of incomes would support the servicing of debts despite precautionary actions on the part of the government and the private sector over time an increasing mass of decisions and contracts came to rely on the sustainability of the real exchange rate in the late 1990s exports stopped rising and the foreign supply of credit tightened the economy contracted in the face of these constraints and the solvency of the government was called into question the financial system was vulnerable both in the event of devaluation and in the event of a large deflation cum adjustment convertibility proved to have very large exit costs as was implicit in its design and management

information theoretic approaches in economics economics has seen a recent rise in interest in information theory as an alternative framework to the conventional notion of equilibrium as a fixed state such as walrasian market clearing general equilibrium the information theoretic approach is predicated on the notion of statistical equilibrium se that takes a distribution over all possible states as an equilibrium and therefore predicts the endogenous fluctuations of the system along with its central tendency simultaneously for this reason se approaches can explain the observed data without relying on arbitrary assumptions about random noise and provide useful insights for many interesting economic problems that conventional methods have not been able to satisfactorily deal with in this paper we review the key elements of information theory focusing on the notions and applications of entropy and se in economics particularly paying attention to how entropy concepts open up a new frontline of economic research

asymmetric competition risk and return distribution abstract we propose a parsimonious statistical model of firm competition where structural differences in the strength of competitive pressure and the magnitude of return fluctuations above and below the system wide benchmark translate into a skewed subbotin or asymmetric exponential power aep distribution of returns to capital empirical evidence from us data illustrates that the aep distribution compares favorably to popular alternative models such as the symmetric or asymmetric laplace density in terms of goodness of fit when entry and exit dynamics of markets are taken into account

gibrat s law redux think profitability instead of growth we argue that firm profitability can be conveniently characterized by one and the same diffusion process for all firms akin to gibrat s seminal idea of a common stochastic description for the dynamics of firm growth here we show that the diffusion of profit rates applies across all surviving corporations irrespective of their size or industry which is not true for growth rates the diffusion process is empirically consistent with both the cross sectional distribution of profit rates and the individual time series of corporate profit rates leading to the notion of a statistical equilibrium this has stark and unexpected implications for our understanding of individual destinies since the model and data suggest that idiosyncratic efforts have no impact on the aggregate distributional outcome instead idiosyncratic efforts merely affect the individual persistence of abnormal profits from the system wide norm put differently corporations have to participate in the same game and can merely choose the speed at which they play it but they cannot bend the rules

scraped data and sticky prices i use daily prices collected from online retailers in five countries to study the impact of measurement bias on three common price stickiness statistics relative to previous results i find that o

implications of rational inattention abstract a constraint that actions can depend on observations only through a communication channel with finite shannon capacity is shown to be able to play a role very similar to that of a signal extraction problem or an adjustment cost in standard control problems the resulting theory looks enough like familiar dynamic rational expectations theories to suggest that it might be useful and practical while the implications for policy are different enough to be interesting

consumption versus expenditure previous authors have documented a dramatic decline in food expenditures at the time of retirement we show that this is matched by an equally dramatic rise in time spent shopping for and preparing meals using a novel data set that collects detailed food diaries for a large cross section of u s households we show that neither the quality nor the quantity of food intake deteriorates with retirement status we also show that unemployed households experience a decline in food expenditure and food consumption commensurate with the impact of job displacement on permanent income these results highlight how direct measures of consumption distinguish between anticipated and unanticipated shocks to income whereas measures of expenditures obscure the distinction