We develop a model of households with multiple needs (smoothing shocks, financing investment) and constraints (limited credit, self-control issues) in order to examine the nature of household's financing constraints in a developing country, and the impact of relaxing them. We show that increased access to credit has very different implications for the aggregate model economy depending on its form: asset-financed or cash. We then illustrate how a short-term increase in access to loans leads to very distinct behavior in the short run. The relevance of the model can be evaluated using a field experiment, which we are currently implementing in Uganda.

We examine the source of the large fall and rebound in US trade in the recent recession. While trade fell and rebounded more than expenditures or production of traded goods, we find that relative to the magnitude of the downturn, these trade fluctuations were in line with those in previous business cycle fluctuations. We argue that the high volatility of trade is attributed to more severe inventory management considerations of firms involved in international trade. We present empirical evidence for autos as well as at the aggregate level that the adjustment of inventory holdings help explain these fluctuations in trade.

We document that delivery lags and transaction-level economics of scale matter for international trade, leading importers to import infrequently and hold additional inventory. In a model with these frictions calibrated to empirical measures of inventory and trade lumpiness, these frictions have a large (20 percent) tariff equivalent, mostly due to inventory carrying costs. These frictions also alter the dynamics of imports and prices. Consistent with evidence from large devaluation episodes in six developing economies, following terms-of-trade and interest rate shocks, the model generates a short-term implosion of imports and a gradual increase in the retail price of imports.

We study the welfare costs of markups in a dynamic model with heterogeneous firms and endogenous markups. We provide aggregation results summarizing the macro implications of micro-level markup heterogeneity. We calibrate our model to US Census of Manufactures data and find that the costs of markups can be large. We decompose the costs into three channels: an aggregate markup that acts like a uniform output tax, misallocation of factors of production, and inefficient entry. We find that the aggregate-markup and misallocation channels account for most of the costs of markups and that the entry channel is much less important.

During the Great Recession, US regions that experienced large declines in household debt also experienced large drops in consumption, employment, and wages. We develop a search and matching model in which tighter debt constraints raise the cost of investing in new job vacancies and so reduce job-finding rates and employment. On-the-job human capital accumulation is critical to generating sizable drops in employment: it increases the duration of the benefit flows from posting vacancies, thereby amplifying the employment drop from a credit tightening 10-fold relative to the standard model. Our model reproduces the salient cross-regional features of the US Great Recession.

Recent work has demonstrated that existing solutions of the unemployment volatility puzzle are at odds with the procylicality of the opportunity cost of employment, the cyclicality of wages, and the volatility of risk-free rates. We propose a model of business cycles that is immune to these critiques by incorporating two key features. First, we allow for preferences that generate time-varying risk over the business cycle to account for observed fluctuations in asset prices. Second, we introduce human capital acquisition, as is consistent with the evidence on how wages grow with experience in the labor market. Our model reproduces the observed fluctuations in unemployment because hiring a worker is a risky investment with long-duration returns. As in the data, the price of risk in our model sharply increases in recessions. The benefit from hiring new workers therefore greatly declines, leading to a large decrease in job vacancies and an increase in unemployment of the same magnitude as in the data. We show that our results extend to versions of the model that include physical capital, a life cycle for workers, and alternative preference structures common in the asset-pricing literature.