Economic growth and complementarity between stages of human capital

We study the impact of the different stages of human capital accumulation on the evolution of labor productivity in a model calibrated to the U.S. from 1961 to 2008. We add early childhood education to a standard continuous time life cycle economy and assume complementarity between educational stages. There are three sectors in the model: the goods sector, the early childhood sector and the formal education sector. Agents are homogenous and choose the intensity of preschool education, how long to stay in formal school, labor effort and consumption, and there are exogenous distortions to these four decisions. The model matches the data very well and closely reproduces the paths of schooling, hours worked, relative prices and GDP. We find that the reduction in distortions to early education in the period was large and made a very strong contribution to human capital accumulation. However, due to general equilibrium effects of labor market taxation, marginal modification in the incentives for early education in 2008 had a smaller impact than those for formal education. This is because the former do not decisively affect the decision to join the labor market, while the latter do. Without labor taxation, incentives for preschool are significantly stronger.

Health Care Reform or More Affordable Health Care?

This article investigates the impact on the U.S. economy of making health care more affordable. We compare health care cost reductions with the Patient Protection and Affordable Care Act (PPACA) using a rich life cycle general equilibrium model with heterogeneous agents. We found that all policies were able to reduce uninsured population, but the PPACA was the most effective: in the long run, less than 5% of Americans would remain uninsured. Cost reductions alleviated the government budget, while tax hikes were needed to finance the reform. Feasible cost reductions are less welfare improving than the PPACA.

First-Price auction symmetric equlibria with a general distribution

In this paper I obtain the mixed strategy symmetric equilibria of the first-price auction for any distribution. The equilibrium is unique. The solution turns out to be a combination of absolutely continuous distributions case and the discrete distributions case.

First-price auction symmetric equilibria with a general distribution

In this paper I obtain the mixed strategy symmetric equilibria of the first-price auction for any distribution. The equilibrium is unique. The solution turns out to be a combination of absolutely continuous distributions case and the discrete distributions case.

Bubbles, collateral and monetary equilibrium

Consider an economy where infinite-lived agents trade assets collateralized by durable goods. We obtain results that rule out bubbles when the additional endowments of durable goods are uniformly bounded away from zero, regardless of whether the asset’s net supply is positive or zero. However, bubbles may occur, even for state-price processes that generate finite present value of aggregate wealth. First, under complete markets, if the net supply is being endogenously reduced to zero as a result of collateral repossession. Secondly, under incomplete markets, for a persistent positive net supply, under the general conditions guaranteeing existence of equilibrium. Examples of monetary equilibria are provided.

Affiliation, equilibrium existence and the revenue ranking of auctions

We consider private value auctions where bidders’ types are dependent, a case usually treated by assuming affiliation. We show that affiliation is a restrictive assumption in three senses: topological, measure-theoretic and statistical (affiliation is a very restrictive characterization of positive dependence). We also show that affiliation’s main implications do not generalize for alternative definitions of positive dependence. From this, we propose new approaches to the problems of pure strategy equilibrium existence in first-price auctions (PSEE) and the characterization of the revenue ranking of auctions. For equilibrium existence, we slightly restrict the set of distributions considered, without loss of economic generality, and offer a complete characterization of PSEE. For revenue ranking, we obtain a characterization of the expected revenue differences between second and first price auctions with general dependence of types.