I develop a model of (individually rational) collective reality denial in groups, organizations and markets. Whether participants' tendencies toward wishful thinking reinforce or dampen each other is shown to hinge on a simple and novel mechanism. When an agent can expect to benefit from other's...

This Paper develops a model with multiple steady states (low tax and low unemployment versus high tax and high unemployment) in which equilibrium selection is not conditioned on a sunspot variable. Instead, large temporary shocks initiate unavoidable transitions from one steady state to another....

We develop a dynamic model of liquidity provision, in which hedgers can trade multiple risky assets with arbitrageurs. We compute the equilibrium in closed form when arbitrageurs' utility over consumption is logarithmic or risk-neutral with a non-negativity constraint. Liquidity is increasing in...

We develop a model of financially constrained arbitrage, and use it to study the dynamics of arbitrage capital, liquidity, and asset prices. Arbitrageurs exploit price discrepancies between assets traded in segmented markets, and in doing so provide liquidity to investors. A collateral...

This paper studies how organizational design affects moral outcomes. Subjects face the decision to either kill mice for money or to save mice. We compare a Baseline treatment where subjects are fully pivotal to a Diffused-Pivotality treatment where subjects simultaneously choose in groups of...

The paper studies the causes of the current financial crisis and considers proposals for mitigation and prevention of future crises. The crisis is was the product of a ‘perfect storm’ bringing together a number of microeconomic and macroeconomic pathologies. Among the microeconomic systemic...

Expectations play a central role in modern macroeconomics. The econometric learning approach, in line with the cognitive consistency principle, models agents as forming expectations by estimating and updating subjective forecasting models in real time. This approach provides a stability test for...

This paper considers a general class of nonlinear rational-expectations models in which policymakers seek to maximize an objective function that may be household expected utility. We show how to derive a target criterion that is: (i) consistent with the model's structural equations, (ii) strong...

In this paper we consider a Ramsey one-sector model with non-separable homothetic preferences, endogenous labour and productive external effects arising from average capital and labour. We show that indeterminacy cannot arise when there are only capital externalities but that it does when there...

In this paper, we consider an aggregate overlapping generations model with endogenous labour, consumption in both periods of life, homothetic preferences and productive external effects coming from the average capital and labour. We show that under realistic calibrations of the parameters, in...