Publications



What are the aggregate effects of informality in a financially constrained economy? We develop and calibrate an entrepreneurship model to data on matched employer-employee from both formal and informal sectors in Brazil. The model distinguishes between informality on the business side (extensive margin) and the informal hiring by formal firms (intensive margin). We find that when informality is eliminated along both margins, aggregate output increases 9.3%, capital 14.7%, TFP 5.4%, and tax revenue 37%. The output and TFP increases would be much larger if informality were only eliminated on the extensive margin, a result that supports the view that the informal economy can play a positive role in an economy with financial frictions. Finally, we find that the output cost of financing social security in our baseline model is about twice as large as the one in an economy with no frictions.


Goldin (2014) offers a narrative in which gender differences in home production responsibilities create gender gaps in labor market outcomes. We carry out a model-based quantitative assessment of this narrative and find that empirically reasonable gender differences in home production time account for a significant share of gender gaps in three labor market outcomes: occupational choice, wages, and hours. Our analysis emphasizes two key elements not highlighted by Goldin (2014). One is heterogeneity in comparative advantage. This feature generates selection effects that are crucial for the model to be consistent with the fact that the gender wage gap is uncorrelated with occupational mean hours. Second, we explicitly model multi-member households that make joint decisions about occupational choice and hours of market work. Family interactions are a quantitatively important source of amplification. Gender differences in non-market responsibilities can have important aggregate effects on welfare and productivity, similar to those emphasized by Hsieh et al. (2019).


The Hopenhayn and Rogerson (1993) framework is extended to understand how different forms of taxing capital income affect firms’ investment and financial policies over their life cycle. Relative to dividends and capital gains taxation, corporate income taxation slows down firm growth over the life cycle by reducing after-tax profits available for reinvesting. It also diminishes entry by negatively affecting the value of entrants relative to that of incumbent firms. After a tax reform eliminating the corporate income tax in a revenue-neutral way, output and capital increased by 12% and 32%. The large response of firm entry is crucial.


The Lucas (1978) model is extended to incorporate heterogeneity in working ability and a time allocation decision by entrepreneurs (work versus manage). Financial frictions distort not only the average skill of entrepreneurs but also the average skill of workers. The model economy accounts for half of the association between entrepreneurship and external finance to GDP in the data, whereas a standard span of control model explains only about one-tenth. The variation in entrepreneurship is mostly due to the variation in self-employed entrepreneurs rather than in employers. Moreover, financial frictions have larger effects on output per worker, TFP, and inequality.


We build a heterogeneous life-cycle model which captures a large number of salient features of individual male labor supply over the life cycle, by education, both along the intensive and extensive margins. The model provides an aggregation theory of individual labor supply, firmly grounded on individual-level micro evidence, and is used to study the aggregate labor supply responses to changes in the economic environment. We find that the aggregate labor supply elasticity to a transitory wage shock is 1.75, with the extensive margin accounting for 62% of the response. Furthermore, we find that the aggregate labor supply elasticity to a permanent-compensated wage change is 0.44.


This paper measures how much of the gender wage gap over the  lifecycle is due to the  fact that working hours are lower for women than for men. We build a quantitative theory of fertility, labor supply, and human capital accumulation decisions to measure gender differences in human capital investments over the lifecycle. We assume tha tthere are no gender differences in the human capital technology and calibrate this technology using wage–age profiles of men. The calibration of females assumes that children involves a forced reduction in hours of work that falls on females rather than on males and that there is an exogenous gender gap in hours of work. We find that our theory accounts for all of the increase in the gender wage gap over the lifecycle in the NLSY79 data. The impact of children on the labor supply of females accounts for 56% and 45% of the increase in the gender wage gap over the lifecycle among non-college and college females, while the rest is due to the exogenous gender differences in hours of work. 


There are substantial cross-country differences in labor supply late in the life cycle (age 50+). A theory of labor supply and retirement decisions is developed to quantitatively assess the role of social security, disability insurance, and taxation for understanding differences in labor supply late in the life cycle across European countries and the United States. The findings support the view that government policies can go a long way towards accounting for the low labor supply late in the life cycle in the European countries relative to the United States, with social security rules accounting for the bulk of these effects.


We build a model of heterogeneous individuals—who make investments in schooling quantity and quality—to quantify the importance of differences in human capital vs. total factor productivity (TFP) in explaining the variation in per capita income across countries. The production of human capital requires expenditures and time inputs; the relative importance of these inputs determines the predictions of the theory for inequality both within and across countries. We discipline our quantitative assessment with a calibration firmly grounded on US micro evidence. Since in our calibrated model economy human capital production requires a significant amount of expenditures, TFP changes affect disproportionately the benefits and costs of human capital accumulation. Our main finding is that human capital accumulation strongly amplifies TFP differences across countries: to explain a 20-fold difference in the output per worker, the model requires a 5-fold difference in the TFP of the tradable sector, vs. an 18-fold difference if human capital is fixed across countries.


There are substantial cross-country differences in labor supply late in the life cycle (age 50+). A theory of labor supply and retirement decisions is developed to quantitatively assess the role of social security, disability insurance, and taxation for understanding differences in labor supply late in the life cycle across European countries and the United States. The findings support the view that government policies can go a long way towards accounting for the low labor supply late in the life cycle in the European countries relative to the United States, with social security rules accounting for the bulk of these effects.


Abstract: We develop a theory of capital-market imperfections to study how the ability to enforce contracts affects resource allocation across entrepreneurs of different productivities, and across industries with different needs for external financing. The theory implies that countries with a poor ability to enforce contracts are characterized by the use of inefficient technologies, low aggregate TFP, large differences in labor productivity across industries, and large employment shares in industries with low productivity. These implications are supported by the empirical evidence. The theory also suggests that entrepreneurs have a vested interest in maintaining a status quo with low enforcement.


We study optimal allocations in an environment in which money is essential due to lack of commitment and anonymity of individuals. Because the economy features aggregate preference shocks, we apply a notion of implementability that allows for allocations with non-trivial business-cycle dynamics for the propagation of shocks. We show that history dependence is predicted by the theory of second best and becomes necessary for optimality when the degree of patience is neither too low nor too high. Our analysis concludes with a discussion of whether there is a role for the propagation of shocks in alternative economic environments.


We develop a quantitative theory of economic inequality to investigate the effects of replacing the current U.S. progressive income tax system with a proportional one. The cross-sectional implications of the theory are used to discipline the assessment of the effects of tax policy and circumvent the lack of conclusive micro-evidence on the parameterization of the human capital production technology. We find that the elimination of progressive taxation increases steady state level of output by 12.6%, capital by 21.8%, and consumption by 13.2%. Moreover, it increases economic inequality and its persistence across generations.


We present a theory concerning the realization of capital gains where ownership and control are linked as in Holmes and Schmitz (J. Pol. Econ. 103: 1005–1038, 1995). The model developed is a version of a Lucas-tree economy in which the productivity of a technology depends on the ownership of the technology. The existence and uniqueness of equilibrium follow from the Contraction Mapping Theorem. The theory implies that impediments to asset trading, such as capital gains taxation, negatively affect production efficiency. Moreover, we calibrate the model economy to U.S. data on small-business turnover and find that indexing deductions for inflation is capable of increasing capital-gains tax revenues.


We build on our earlier model of money in which bank liabilities circulate as a medium of exchange. We investigate optimal bank behavior and the resulting provision of liquidity under a range of central bank regulations. In our model, banks issue inside money under fractional reserves, facing the possibility of excess redemptions. Banks consider the float resulting from money creation and make reserve-management decisions that affect aggregate liquidity conditions. Numerical examples demonstrate positive bank failure rates when returns to banking are low. Central bank interventions may improve banks' returns and welfare through a reduction in bank failure.


Abstract: Evidence on the portfolio holdings and transaction patterns of households suggests that the burden of inflation is not evenly distributed. We build a monetary growth model consistent with key features of cross- sectional household data and use this framework to study the distributional impact of inflation. At the aggregate level, our model economy behaves similarly to standard monetary growth models within the representative agent abstraction. Inflation has, however, important distributional effects since it is effectively a regressive consumption tax. Thus, neglecting the distributional consequences of inflation may prove misleading in assessing the effects of inflation in our economy.


We use a very standard life-cycle growth model, in which individuals have a labor-leisure choice in each period of their lives, to prove that an optimizing government will almost always find it optimal to tax or subsidize interest income. The intuition for our result is straightforward. In a life-cycle model the individual?s optimal consumption-work plan is almost never constant and an optimizing government almost always taxes consumption goods and labor earnings at different rates over an individual?s lifetime. One way to achieve this goal is to use capital and labor income taxes that vary with age. If tax rates cannot be conditioned on age, a non-zero tax on capital income is also optimal, as it can (imperfectly) mimic age-conditioned consumption and labor income tax rates.


A striking observation of the U.S. and other labor markets is the weak position of women in terms of job attachment, employment, and earnings relative to men. We develop a model of fertility and labor market decisions to study the impact of fertility on gender differences in labor turnover, employment, and wages. In our framework, individuals search for jobs and accumulate general (experience) and specific (tenure) human capital when they work. They can also increase their wage by moving to a job of higher quality. Labor market decisions (e.g., job acceptance and job mobility) may differ across genders: females that give birth may decide to interrupt their labor market attachment in order to enjoy the value of staying at home with their children. The model economy is successfully calibrated to match aggregate statistics in terms of fertility, employment, and wages. We find that fertility decisions generate important gender differences in turnover rates, with long lasting effects in employment and wages. These differences in labor turnover account for almost all the U.S. gender wage gap that is attributed to labor market experience by Blau and Kahn (2000, Journal of Labor Economics 15 (1), 1-42). The model also implies a very small role of tenure capital in accounting for wage differences between males and females (gender gap), and between females with and without children (family gap).


This paper presents evidence that the spread between the marginal product of capital and the return on financial assets is much higher in poor than in rich countries. A model with costly intermediation is developed. In this economy, individuals choose at each instant whether to work or to operate a technology. Entrepreneurs finance their business with their own savings and, if necessary, by borrowing from banks. I find that in this framework intermediation costs are not equivalent to a tax on the return of capital. The equivalence fails because costly intermediation not only affects the capital accumulation decision but also the occupational choice decision. I show that intermediation costs have important effects on per capita output and average business size in the economy. I conclude that taxing financial intermediaries can be a very bad policy for development.


We introduce an element of centralization in a random matching model of money that allows for private liabilities to circulate as media of exchange. Some agents. which we identify as banks, are endowed with the technology to issue notes and to record-keep reserves with a central clearinghouse! ·which we call the treasury. The liabilities are redeemed according to a stochastic process that depends on the endogenous trades. The treasury removes the banking technology from banks that are not able to meet the redemptions in a given period. This together with the market incompleteness gives rise to a reserve management problem for the issuing banks. We demonstrate that "sufficiently patient" banks will concentrate on improving their reserve position instead of pursuing additional issue. The model provides a first attempt to reconcile limited note issue with optimizing behavior by banks during the National Banking Era.


Non-Refereed Publications: 

A survey of the literature on optimal taxation both in infinitely-lived agent models and life-cycle economies suggests that no consensus emerges regarding the optimal tax rate on capital income. Although the tax rate is invariably zero in the long-run steady state of infinitely-lived agent models, this same zero-tax prescription holds for life-cycle economies only under extremely stringent conditions. Both models suggest that capital income should be taxed at non-zero rates during the transition to long-run equilibrium unless individuals have separable preferences between consumption and leisure.