Research Database

We document how export quantities and prices evolve after entry to a market. Controlling for marginal cost, and taking account of selection on idiosyncratic demand, there are economically and statistically significant dynamics of quantities, but no dynamics of prices. To match these facts, we estimate a model where firms invest in customer base through non-price actions (e.g. marketing and advertising), and learn gradually about their idiosyncratic demand. The model matches quantity, price and exit moments. Parameter estimates imply costs of adjusting investment in customer base, and slow learning about demand, both of which generate sluggish responses of sales to shocks.

We explore quantitatively the possibility of multiple equilibria in a model of sovereign debt crises. The source of multiplicity is the one identified by Calvo (1988). This type of multiplicity has been at the heart of the policy debate through the recent European sovereign debt crisis. Key for multiplicity in the model is a stochastic process for output featuring long periods of either high or low growth. We calibrate the output process in the model using data for the southern European countries that were exposed to the debt crisis. We find that expectations-driven sovereign debt crises are empirically plausible, but only in periods of stagnation. Multiplicity is state dependent: in periods of stagnation and for intermediate levels of debt, interest rates may be high for reasons unrelated to fundamentals.

We show how to use panel data on household consumption to directly estimate households’ risk preferences. Specifically, we measure heterogeneity in risk aversion among households in Thai villages using a full risk-sharing model, which we then test allowing for this heterogeneity. There is substantial, statistically significant heterogeneity in estimated risk preferences. Full insurance cannot be rejected. As the risk sharing, as-if-complete-markets theory might predict, estimated risk preferences are unrelated to wealth or other characteristics. The heterogeneity matters for policy: Although the average household would benefit from eliminating village-level risk, less-risk-averse households who are paid to absorb that risk would be worse off by several percent of household consumption.

We assess the welfare consequences of occupational licensing for workers and consumers. We estimate a model of labor market equilibrium in which licensing restricts labor supply but also affects labor demand via worker quality and selection. On the margin of occupations licensed differently between U.S. states, we find that licensing raises wages and hours but reduces employment. We estimate an average welfare loss of 12 percent of occupational surplus. Workers and consumers respectively bear 70 and 30 percent of the incidence. Higher willingness to pay offsets 80 percent of higher prices for consumers, and higher wages compensate workers for 60 percent of the cost of mandated investment in occupation-specific human capital.

We show that an increase in the minimum wage can have large effects throughout the earnings distribution, using a combination of theory and evidence. To this end, we develop an equilibrium search model featuring empirically relevant worker and firm heterogeneity. The minimum wage induces firms to adjust their equilibrium wage and vacancy policies, leading to spillovers on higher wages. We use the estimated model to evaluate the effects of a 119 percent increase in the real minimum wage in Brazil from 1996 to 2012. The policy change explains a large decline in earnings inequality, with spillovers reaching up to the 80th percentile of the earnings distribution. At the same time, employment and output fall only modestly as workers relocate to more productive firms. Using administrative linked employer-employee data and two household surveys, we find reduced-form evidence in support of the model predictions.

This appendix contains seven sections. Section A reports results from running regressions of labor earnings on GDP using data from the PSID, for comparison with the results using HRS data in the body of the paper. Section B examines the relationship between family income, aggregate shocks, and risk preferences in the PSID. Section C gives technical details on the Markov Chain Monte Carlo estimation employed in table 1 of the paper and reports the complete parameter estimates for the regressions summarized in that table. Section D reports results when the relationship between earnings and aggregate shocks is estimated with individual-specific coecients rather than common coecients for each risk-tolerance group. Section E reports results comparable to table 1 of the paper and table D.1 of this appendix using only Social Security covered earnings instead of the combination of Social Security and W-2 earnings. Section F reports robustness checks for tables 2 and 3 of the paper under alternative definitions of the household and the consumption and income variables. Section G reports robustness checks for tables 2 and 3 under an alternative definition of the leisure variable.

Randomness in individual discovery disperses productivities, whereas learning from others keeps productivities together. Long-run growth and persistent earnings inequality emerge when these two mechanisms for knowledge accumulation are combined. This paper considers an economy in which those with more useful knowledge can teach others, with competitive markets assigning students to teachers. In equilibrium, students with an ability to learn quickly are assigned to teachers with the most productive knowledge. This sorting on ability implies large differences in earnings distributions conditional on ability, as shown using explicit formulas for the tail behavior of these distributions.

Using simulations from a multicountry neoclassical growth model, we analyze several post-Brexit scenarios. First, the United Kingdom unilaterally imposes tighter restrictions on FDI and trade from other EU nations. Second, the European Union retaliates and imposes the same restrictions on the UK. Finally, the United Kingdom reduces restrictions on other nations during the post-Brexit transition. Model predictions depend crucially on the policy response of multinationals’ investment in technology capital, accumulated know-how from investments in R&D, brands, and organizations used simultaneously in their domestic and foreign operations.

This essay articulates the principles and practices of New Monetarism, our label for a recent body of work on money, banking, payments, and asset markets. We first discuss methodological issues distinguishing our approach from others: New Monetarism has something in common with Old Monetarism, but there are also important differences; it has little in common with Keynesianism. We describe the principles of these schools and contrast them with our approach. To show how it works, in practice, we build a benchmark New Monetarist model, and use it to study several issues, including the cost of inflation, liquidity and asset trading. We also develop a new model of banking.

We build a variation of the neoclassical growth model in which both wealth shocks (in the sense of wealth destruction) and financial shocks to households generate recessions. The model features three mild departures from the standard model: (1) adjustment costs make it difficult to expand the tradable goods sector by reallocating factors of production from nontradables to tradables; (2) there is a mild form of labor market frictions (Nash bargaining wage setting with Mortensen-Pissarides labor markets); (3) goods markets for nontradables require active search from households wherein increases in consumption expenditures increase measured productivity. These departures provide a novel quantitative theory to explain recessions like those in southern Europe without relying on technology shocks.

We develop a pair of risk measures, health and mortality delta, for the universe of life and health insurance products. A life-cycle model of insurance choice simplifies to replicating the optimal health and mortality delta through a portfolio of insurance products. We estimate the model to explain the observed variation in health and mortality delta implied by the ownership of life insurance, annuities including private pensions, and long-term care insurance in the Health and Retirement Study. For the median household aged 51 to 57, the lifetime welfare cost of market incompleteness and suboptimal choice is 3.2% of total wealth.

We develop a new general equilibrium model of asset pricing and asset trading volume in which agents’ motivations to trade arise due to uninsurable idiosyncratic shocks to agents’ risk tolerance. In response to these shocks, agents trade to rebalance their portfolios between risky and riskless assets. We study a positive question — When does trade volume become a pricing factor? — and a normative question — What is the impact of Tobin taxes on asset trading on welfare? In our model, economies in which marketwide risk tolerance is negatively correlated with trade volume have a higher risk premium for aggregate risk. Likewise, for a given economy, we find that assets whose cash flows are concentrated on states with high trading volume have higher prices and lower risk premia. We then show that Tobin taxes on asset trade have a first-order negative impact on ex-ante welfare, i.e., a small subsidy to trade leads to an improvement in ex-ante welfare. Finally, we develop an alternative version of our model in which asset trade arises from uninsurable idiosyncratic shocks to agents’ hedging needs rather than shocks to their risk tolerance. We show that our positive results regarding the relationship between trade volume and asset prices carry through. In contrast, the normative implications of this specification of our model for Tobin taxes or subsidies depend on the specification of agents’ preferences and non-traded endowments.

What shapes the optimal degree of progressivity of the tax and transfer system? On the one hand, a progressive tax system can counteract inequality in initial conditions and substitute for imperfect private insurance against idiosyncratic earnings risk. On the other hand, progressivity reduces incentives to work and to invest in skills, distortions that are especially costly when the government must finance public goods. We develop a tractable equilibrium model that features all of these trade-offs. The analytical expressions we derive for social welfare deliver a transparent understanding of how preference, technology, and market structure parameters influence the optimal degree of progressivity. A calibration for the U.S. economy indicates that endogenous skill investment, flexible labor supply, and the desire to finance government purchases play quantitatively similar roles in limiting optimal progressivity. In a version of the model where poverty constrains skill investment, optimal progressivity is close to the U.S. value. An empirical analysis on cross-country data offers support to the theory.

We study fiscal and monetary policy in a monetary union with the potential for rollover crises in sovereign debt markets. Member-country fiscal authorities lack commitment to repay their debt and choose fiscal policy independently. A common monetary authority chooses inflation for the union, also without commitment. We first describe the existence of a fiscal externality that arises in the presence of limited commitment and leads countries to over-borrow; this externality rationalizes the imposition of debt ceilings in a monetary union. We then investigate the impact of the composition of debt in a monetary union, that is the fraction of high-debt versus low-debt members, on the occurrence of self-fulfilling debt crises. We demonstrate that a high-debt country may be less vulnerable to crises and have higher welfare when it belongs to a union with an intermediate mix of high- and low-debt members, than one where all other members are low-debt. This contrasts with the conventional wisdom that all countries should prefer a union with low-debt members, as such a union can credibly deliver low inflation. These findings shed new light on the criteria for an optimal currency area in the presence of rollover crises.

We develop a new tractable model of banks' liquidity management and the credit channel of monetary policy. Banks finance loans by issuing demand deposits. Because loans are illiquid, deposit transfers across banks must be settled with reserves. Deposit withdrawals are random, and banks manage liquidity risk by holding a precautionary buffer of reserves. We show how different shocks affect the banking system by altering the trade-off between profiting from lending and incurring greater liquidity risk. Through various tools, monetary policy affects the real economy by altering that trade-off. In a quantitative application, we study the driving forces behind the decline in lending and liquidity hoarding by banks during the 2008 financial crisis. Our analysis underscores the importance of disruptions in interbank markets followed by a persistent decline in credit demand.

What structure of income taxation maximizes the social benefits of redistribution while minimizing the social harm associated with distorting the allocation of labor input? Many authors have advocated scrapping the current tax system, which redistributes primarily via marginal tax rates that rise with income, and replacing it with a flat tax system, in which marginal tax rates are constant and redistribution is achieved via non-means-tested transfers. In this paper we compare alternative tax systems in an environment with distinct roles for public and private insurance. We evaluate alternative policies using a social welfare function designed to capture the taste for redistribution reflected in the current tax system. In our preferred specification, moving to the optimal flat tax policy reduces welfare, whereas moving to the optimal fully nonlinear Mirrlees policy generates only tiny welfare gains. These findings suggest that proposals for dramatic tax reform should be viewed with caution.

Does competition spur productivity? And if so, how does it do so? These have long been regarded as central questions in economics. This essay reviews the literature that makes progress toward answering both questions.

We develop a model of equilibrium price dispersion via retailer search and show that the degree of market segmentation within and across countries cannot be separately identified by good-level price data alone. We augment a set of well-known empirical facts about the failure of the law of one price with data on aggregate intranational and international trade quantities, and calibrate the model to match price and quantity facts simultaneously. The calibrated model matches the data very well and implies that within-country markets are strongly segmented, while international borders contribute virtually no additional market segmentation.

We study the large observed changes in labor supply by married women in the United States over the post–World War II period, a period that saw little change in the labor supply by single women. We investigate the effects of changes in the gender wage gap, the quantitative impact of technological improvements in the production of nonmarket goods, and the potential inferiority of nonmarket goods in explaining the dramatic change in labor supply. We find that small decreases in the gender wage gap can simultaneously explain the significant increases in the average hours worked by married women and the relative constancy in the hours worked by single women and by single and married men. We also find that the impact of technological improvements in the household on married female hours and on the relative wage of females to males is too small for realistic values. Some specifications of the inferiority of home goods match the hours patterns, but they have counterfactual predictions for wages and expenditure patterns.

Does the pattern of social connections between individuals matter for macroeconomic outcomes? If so, where do these differences come from and how large are their effects? Using network analysis tools, we explore how different social network structures affect technology diffusion and thereby a country's rate of growth. The correlation between high-diffusion networks and income is strongly positive. But when we use a model to isolate the effect of a change in social networks, the effect can be positive, negative, or zero. The reason is that networks diffuse ideas and disease. Low-diffusion networks have evolved in countries where disease is prevalent because limited connectivity protects residents from epidemics. But a low-diffusion network in a low-disease environment needlessly compromises the diffusion of good ideas. In general, social networks have evolved to fit their economic and epidemiological environment. Trying to change networks in one country to mimic those in a higher-income country may well be counterproductive.

The Pareto-like tail of the size distribution of firms can arise from random growth of productivity or stochastic accumulation of capital. If the shocks that give rise to firm growth are perfectly correlated within a firm, then the growth rates of small and large firms are equally volatile, contrary to what is found in the data. If firm growth is the result of many independent shocks within a firm, it can take hundreds of years for a few large firms to emerge. This paper describes an economy with both types of shocks that can account for the thick-tailed firm size distribution, high entry and exit rates, and the relatively young age of large firms. The economy is one in which aggregate growth is driven by the creation of new products by both new and incumbent firms. Some new firms have better ideas than others and choose to implement those ideas at a more rapid pace. Eventually, such firms slow down when the quality of their ideas reverts to the mean. As in the data, average growth rates in a cross section of firms will appear to be independent of firm size, for all but the smallest firms.

This paper presents a continuous-time model of sovereign debt. In it, a relatively impatient sovereign government’s hidden type switches back and forth between a commitment type, which cannot default, and an optimizing type, which can default on the country’s debt at any time, and assume outside lenders have particular beliefs regarding how a commitment type should borrow for any given level of debt and bond price. We show that if these beliefs satisfy reasonable assumptions, in any Markov equilibrium, the optimizing type mimics the commitment type when borrowing, revealing its type only by defaulting on its debt at random times. Further, in such Markov equilibria (the solution to a simple pair of ordinary differential equations), there are positive gross issuances at all dates, constant net imports as long as there is a positive equilibrium probability that the government is the optimizing type, and net debt repayment only by the commitment type. For countries that have recently defaulted, the interest rate the country pays on its debt is a decreasing function of the amount of time since its last default, and its total debt is an increasing function of the amount of time since its last default. For countries that have not recently defaulted, interest rates are constant.

The direct benefits of infrastructure in developing countries can be large, but if new infrastructure induces in-migration, congestion of other local publicly provided goods may offset the direct benefits. Using the example of rural household electrification in South Africa, we demonstrate the importance of accounting for migration when evaluating welfare gains of spatial programs. We also provide a practical approach to computing welfare gains that does not rely on land prices. We develop a location choice model that incorporates missing land markets and allows for congestion in local land. Using this model, we construct welfare bounds as a function of the income and population effects of the new electricity infrastructure. A novel prediction from the model is that migration elasticities and congestion effects are especially large when land markets are missing. We empirically estimate these welfare bounds for rural electrification in South Africa and show that congestion externalities from program-induced migration reduced local welfare gains by about 40%.

Modern business cycle theory focuses on the study of dynamic stochastic general equilibrium models that generate aggregate fluctuations similar to those experienced by actual economies. We discuss how this theory has evolved from its roots in the early real business cycle models of the late 1970s through the turmoil of the Great Recession four decades later. We document the strikingly different pattern of comovements of macro aggregates during the Great Recession compared to other postwar recessions, especially the 1982 recession. We then show how two versions of the latest generation of real business cycle models can account, respectively, for the aggregate and the cross-regional fluctuations observed in the Great Recession in the United States.

This paper uses an estimated structural model to argue that the option to move in and out of the parental home is an important insurance channel against labor market risk for youths who do not attend college. Using data from the NLSY97, I construct a new monthly panel of parent-youth coresidence outcomes and use it to document an empirical relationship between these movements and individual labor market events. The data is then used to estimate the parameters of a dynamic game between youths and their altruistic parents, featuring coresidence, labor supply and savings decisions. Parents can provide both monetary support through explicit financial transfers, and non-monetary support in the form of shared residence. To account for the data, two types of exogenous shocks are needed. Preference shocks are found to explain most of the cross-section of living arrangements, while labor market shocks account for individual movements in and out of the parental home. I use the model to show that coresidence is a valuable form of insurance, particularly for youths from poorer families. The option to live at home also helps to explain features of aggregate data for low-skilled young workers: their low savings rates and their relatively small consumption responses to labor market shocks. An important implication is that movements in and out of home can reduce the consumption smoothing benefits of social insurance programs.

We use balance sheet data and stock market data for the major U.S. banking institutions during and after the 2007-8 financial crisis to estimate the magnitude of the losses experienced by these institutions because of the crisis. We then use these estimates to assess the impact of the crisis under alternative, and higher, capital requirements. We find that substantially higher capital requirements (in the 20% to 30% range) would have substantially reduced the vulnerability of these financial institutions, and consequently they would have significantly reduced the need of a public bailout.

This paper proposes a new way of modeling age, period, and cohort effects that improves substantively and methodologically on the conventional linear model. The linear model suffers from a well-known identification problem: If we assume an outcome of interest depends on the sum of an age effect, a period effect, and a cohort effect, then it is impossible to distinguish these three separate effects because, for any individual, birth year = current year – age. Less well appreciated is that the model also suffers from a conceptual problem: It assumes that the influence of age is the same in all time periods, the influence of present conditions is the same for people of all ages, and cohorts do not change over time. We argue that in many applications, these assumptions fail. We propose a more general model in which age profiles can change over time and period effects can have different influences on people of different ages. Our model defines cohort effects as an accumulation of age-by-period interactions. Although a long-standing literature on theories of social change conceptualizes cohort effects in exactly this way, we are the first to show how to statistically model this more complex form of cohort effects. We show that the additive model is a special case of our model and that, except in special cases, the parameters of the more general model are identified. We apply our model to analyze changes in age-specific mortality rates in Sweden over the past 150 years. Our model fits the data dramatically better than the additive model. The estimates show that the rate of increase of mortality with age among adults became more steep from 1881 to 1941, but since then the rate of increase has been roughly constant. The estimates also allow us to test whether early-life conditions have lasting impacts on mortality, as under the cohort morbidity phenotype hypothesis. The results give limited support to this hypothesis: The impact of early-life conditions lasts for several years but is unlikely to reach all the way to old age.

Applied general equilibrium (AGE) models, which feature multiple countries, multiple industries, and input-output linkages across industries, have been the dominant tool for evaluating the impact of trade reforms since the 1980s. We review how these models are used to perform policy analysis and document their shortcomings in predicting the industry-level effects of past trade reforms. We argue that, to improve their performance, AGE models need to incorporate product-level data on bilateral trade relations by industry and better model how trade reforms lower bilateral trade costs. We use the least traded products methodology of Kehoe et al. (2015) to provide guidance on how improvements can be made. We provide further suggestions on how AGE models can incorporate recent advances in quantitative trade theory to improve their predictive ability and better quantify the gains from trade liberalization.

This paper develops an overlapping generations model to study the macroeconomic effects of an unexpected elimination of Medicare. We find that a large share of the elderly respond by substituting Medicaid for Medicare. Consequently, the government saves only 46 cents for every dollar cut in Medicare spending. We argue that a comparison of steady states is insufficient to evaluate the welfare effects of the reform. In particular, we find lower ex-ante welfare gains from eliminating Medicare when we account for the costs of transition. Lastly, we find that a majority of the current population benefits from the reform but that aggregate welfare, measured as the dollar value of the sum of wealth equivalent variations, is higher with Medicare.

After the economic reforms that followed the National Revolution of the 1950s, Bolivia seemed positioned for sustained growth. Indeed, it achieved unprecedented growth from 1960 to 1977. Mistakes in economic policies, especially the rapid accumulation of debt due to persistent deficits and a fixed exchange rate policy during the 1970s, led to a debt crisis that began in 1977. From 1977 to 1986, Bolivia lost almost all the gains in GDP per capita that it had achieved since 1960. In 1986, Bolivia started to grow again, interrupted only by the financial crisis of 1998–2002, which was the result of a drop in the availability of external financing. Bolivia has grown since 2002, but government policies since 2006 are reminiscent of the policies of the 1970s that led to the debt crisis, in particular, the accumulation of external debt and the drop in international reserves due to a de facto fixed exchange rate since 2012.

We analyze commitment to employment in an environment in which an infinitely lived firm faces a sequence of finitely lived workers who differ in their ability to produce output. A worker’s ability is initially unknown to both the worker and the firm. A worker’s effort affects the information on ability conveyed by his performance. We characterize equilibria and show that they display commitment to employment only when effort has a persistent but delayed impact on output. In this case, by providing insurance against early termination, commitment to employment encourages workers to exert effort, thus improving the firm’s ability to identify workers’ talent. The incentive value of commitment to retention helps explain the use of probationary appointments in environments in which there is uncertainty about individual ability.