Knowledge that Transforms

We use data from the Accelerated Benefits demonstration to estimate the impacts of providing newly entitled disability insurance (DI) beneficiaries with health insurance and additional services during the DI program's 24-month Medicare waiting period. While health insurance alone did not increase employment, the additional employment services appeared to have positive short-term impacts on labor market activity. We find a statistically significant increase in employment and earnings in the second calendar year after random assignment; although these findings disappear in the third calendar year. Our results may have implications for disability reform proposals and provisions within the Affordable Care Act.

The aging of the US population undoubtedly will be associated with macroeconomic changes. In particular, some combination of lower consumption growth and increased labor input will ultimately be required. But, the timing of these changes can have important effects on variables like the rate of return to capital and wages. If the adjustment to consumption is slow, which would be the case if budget deficits were allowed to rise significantly as the population ages, then aging is likely to be associated with an increase in the return to capital and a reduction in wages.

Using the most comprehensive developing country dataset ever compiled on air and water pollution and environmental regulations, the paper assesses India's environmental regulations with a difference-in-differences design. The air pollution regulations are associated with substantial improvements in air quality. The most successful air regulation resulted in a modest but statistically insignificant decline in infant mortality. In contrast, the water regulations had no measurable benefits. The available evidence leads us to cautiously conclude that higher demand for air quality prompted the effective enforcement of air pollution regulations, indicating that strong public support allows environmental regulations to succeed in weak institutional settings. (JEL I12, J13, O13, Q53, Q58)

In this paper, I offer two ways in which firms can collude: secret monitoring and infrequent coordination. Such collusion is enforceable with intuitive communication protocols. I make my case in the context of a repeated Cournot oligopoly with flexible production, prices that follow a Brownian motion and no monetary side payments, an environment where it has previously been argued that any collusion is impossible. Trade associations can easily facilitate collusion by mediating communication amongst firms. (JEL D21, D43, L12, L13)

This article studies the full equilibrium dynamics of an economy with financial frictions. Due to highly nonlinear amplification effects, the economy is prone to instability and occasionally enters volatile crisis episodes. Endogenous risk, driven by asset illiquidity, persists in crisis even for very low levels of exogenous risk. This phenomenon, which we call the volatility paradox, resolves the Kocherlakota ( 2000) critique. Endogenous leverage determines the distance to crisis. Securitization and derivatives contracts that improve risk sharing may lead to higher leverage and more frequent crises. (JEL E13, E32, E44, E52, G01, G12, G20)

We provide a simple quantitative general equilibrium model of occupational choice with credit market frictions to analyze the aggregate and distributional effects of asset transfer programs. Asset transfer programs have a positive but transient effect on aggregate productivity, and a negative impact on the aggregate capital stock. On net they have a negative but small effect on per capita income. The effects are very heterogeneous across treated individuals. We compare the results in our model to those from recent randomized control trials and historical natural experiments.

We develop a new methodology to estimate herd behavior in financial markets. We build a model of informational herding that can be estimated with financial transaction data. In the model, rational herding arises because of information-event uncertainty. We estimate the model using data on a NYSE stock (Ashland Inc.) during 1995. Herding occurs often and is particularly pervasive on some days. On average, the proportion of herd buyers is 2 percent; that of herd sellers is 4 percent. Herding also causes important informational inefficiencies in the market, amounting, on average, to 4 percent of the asset's expected value. (JEL C58, D82, D83, G12, G14)

At high enough greenhouse gas concentrations, climate change might conceivably cause catastrophic damages with small but non-negligible probabilities. If the bad tail of climate damages is sufficiently fat, and if the coefficient of relative risk aversion is greater than one, the catastrophe-reducing insurance aspect of mitigation investments could in theory have a strong influence on raising the social cost of carbon. In this paper I exposit the influence of fat tails on climate change economics in a simple stark formulation focused on the social cost of carbon. I then attempt to place the basic underlying issues within a balanced perspective.

This paper examines the possibility that a child's years of schooling could increase in the number of siblings, instead of being diminished by competition for parents' resources: if unable to finance the education of their younger children, parents may do so through their older children's labor income. We examine this possibility in a model combining convex returns to education and credit constraints. Our model predicts correlations among family size, years of schooling and birth order, which would not exist when either of these two elements is absent. Empirical patterns shown in the United States, Mexico, and South Korea support the model predictions.

A principal allocates an object to one of I agents. Each agent values receiving the object and has private information regarding the value to the principal of giving it to him. There are no monetary transfers, but the principal can check an agent’s information at a cost. A favored-agent mechanism specifies a value v* and an agent i*. If all agents other than i* report values below v*, then i* receives the good and no one is checked. Otherwise, whoever reports the highest value is checked and receives the good if and only if her report is confirmed. All optimal mechanisms are essentially randomizations over optimal favored-agent mechanisms. (JEL D82)