Knowledge that Transforms

The neurotransmitter dopamine is central to the emerging discipline of neuroeconomics; it is hypothesized to encode the difference between expected and realized rewards and thereby to mediate belief formation and choice. We develop the first formal test of this theory of dopaminergic function, based on a recent axiomatization by Caplin and Dean [2008A]. These tests are satisfied by neural activity in the nucleus accumbens, an area rich in dopamine receptors. We find evidence for separate positive and negative reward prediction error signals, suggesting that behavioral asymmetries in response to losses and gains may parallel asymmetries in nucleus accumbens activity.

We show that it is very difficult to devise performance-based compensation contracts that reward portfolio managers who generate excess returns while screening out managers who cannot generate such returns. Theoretical bounds are derived on the amount of fee manipulation that is possible under various performance contracts.We show that recent proposals to reform compensation practices, such as postponing bonuses and instituting clawback provisions, will not eliminate opportunities to game the system unless accompanied by transparency in managers' positions and strategies. Indeed, there exists no compensation mechanism that separates skilled from unskilled managers solely on the basis of their returns histories.

This paper studies the theoretical and empirical implications of monetary policy making by committee under four different voting protocols. The protocols are a consensus model, where a supermajority is required for a policy change; an agenda-setting model, where the chairman controls the agenda; a dictator model, where the chairman has absolute power over the committee; and a simple majority model, where policy is determined by the median member. These protocols give preeminence to different aspects of the actual decision-making process and capture the observed heterogeneity in formal procedures across central banks. The models are estimated by maximum likelihood using interest rate decisions by the committees of five central banks, namely the Bank of Canada, the Bank of England, the European Central Bank, the Swedish Riksbank, and the U.S. Federal Reserve. For all central banks, results indicate that the consensus model fits actual policy decisions better than the alternative models. This suggests that despite institutional differences, committees share unwritten rules and informal procedures that deliver observationally equivalent policy decisions.

We present a model with altruistic parents and heterogeneous productivity. We derive two key properties for optimal estate taxation. First, the estate tax should be progressive, so that parents leaving a higher bequest face a lower net return on bequests. Second, marginal estate taxes should be negative, so that all parents face a marginal subsidy on bequests. Both properties can be implemented with a simple nonlinear tax on bequests, levied separately from the income tax. These results apply to other intergenerational transfers, such as educational investments, and are robust to endogenous fertility choices. Both estate or inheritance taxes can implement the optimal allocation, but we show that the inheritance tax has some advantages. Finally, when we impose an ad hoc constraint requiring marginal estate taxes to be nonnegative, the optimum features a zero tax up to an exemption level, and a progressive tax thereafter.

We present a model of intuitive inference, called “local thinking,” in which an agent combines data received from the external world with information retrieved from memory to evaluate a hypothesis. In this model, selected and limited recall of information follows a version of the representativeness heuristic. The model can account for some of the evidence on judgment biases, including conjunction and disjunction fallacies, but also for several anomalies related to demand for insurance.

We empirically document, using U.S. import prices, that on average goods with a high frequency of price adjustment have a long-run pass-through that is at least twice as high as that of low-frequency adjusters. We show theoretically that this relationship should follow because variable mark-ups that reduce longrun pass-through also reduce the curvature of the profit function when expressed as a function of cost shocks, making the firm less willing to adjust its price. We quantitatively evaluate a dynamic menu-cost model and show that the variable mark-up channel can generate significant variation in frequency, equivalent to 37% of the observed variation in the data. On the other hand, the standard workhorse model with constant elasticity of demand and Calvo or state-dependent pricing has difficulty matching the facts.

We provide a graphical illustration of how standard consumer and producer theory can be used to quantify the welfare loss associated with inefficient pricing in insurance markets with selection. We then show how this welfare loss can be estimated empirically using identifying variation in the price of insurance. Such variation, together with quantity data, allows us to estimate the demand for insurance. The same variation, together with cost data, allows us to estimate how insurer's costs vary as market participants endogenously respond to price. The slope of this estimated cost curve provides a direct test for both the existence and nature of selection, and the combination of demand and cost curves can be used to estimate welfare. We illustrate our approach by applying it to data on employer-provided health insurance from one specific company. We detect adverse selection but estimate that the quantitative welfare implications associated with inefficient pricing in our particular application are small, in both absolute and relative terms.

Managers often state that they are reluctant to vary prices for fear of “antagonizing customers.” However, there is no empirical evidence that antagonizing customers through price adjustments reduces demand or profits. We use a 28-month randomized field experiment involving over 50,000 customers to investigate how customers react if they buy a product and later observe the same retailer selling it for less. We find that customers react by making fewer subsequent purchases from the firm. The effect is largest among the firm's most valuable customers: those whose prior purchases were most recent and at the highest prices.

We construct a matrix showing the share of the year 2000 population in every country that is descended from people in different source countries in the year 1500. Using the matrix to adjust indicators of early development so they reflect the history of a population's ancestors rather than the history of the place they live today greatly improves the ability of those indicators to predict current GDP. The variance of early development history of a country's inhabitants is a good predictor for current inequality, with ethnic groups originating in regions having longer histories of organized states tending to be at the upper end of a country's income distribution.

This paper develops a simple technique that controls for “false discoveries,” or mutual funds that exhibit significant alphas by luck alone. Our approach precisely separates funds into (1) unskilled, (2) zero‐alpha, and (3) skilled funds, even with dependencies in cross‐fund estimated alphas. We find that 75% of funds exhibit zero alpha (net of expenses), consistent with the Berk and Green equilibrium. Further, we find a significant proportion of skilled (positive alpha) funds prior to 1996, but almost none by 2006. We also show that controlling for false discoveries substantially improves the ability to find the few funds with persistent performance.