Knowledge that Transforms

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.

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.

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.

Neuroeconomics strives to use knowledge from neuroscience to improve models of decisionmaking. Here we introduce a biologically plausible, drift-diffusion model that is able to jointly predict choice behavior and response times across different choice environments. The model has both normative and positive implications for economics. First, we consistently observe that decisionmakers inefficiently allocate their time to choices for which they are close to indifference. We demonstrate that we can improve subjects' welfare using a simple intervention that puts a time limit on their choices. Second, response times can be used to predict indifference points and the strength of preferences.

We study the Lagos and Wright (2005) model of monetary exchange in the laboratory. With a finite population of sufficiently patient agents, this model has a unique monetary equilibrium and a continuum of non-monetary gift exchange equilibria, some of which Pareto dominate the monetary equilibrium. We find that subjects avoid the gift exchange equilibria in favor of the monetary equilibrium. We also study versions of the model without money where all equilibria involve non-monetary gift exchange. We find that welfare is higher in the model with money than without money, suggesting that money plays a role as an efficiency enhancing coordination device.

We study interdependencies in spousal labor supply by exploiting the design of the French workweek reduction, which introduced exogenous variation in one's spouse's labor supply, at constant earnings. Treated employees work on average two hours less per week. Husbands of treated women respond by reducing their labor supply by about half an hour, consistent with substantial leisure complementarity, and specifically cut the nonusual component of their workweek, leaving usual hours unchanged. Women's response to their husband's treatment is instead weak and rarely statistically significant, possibly due to heavier constraints in the organization of their workweek.

Robert J. Shiller delivered his Prize Lecture on 8 December 2013 at Aula Magna, Stockholm University.