We study how best to reward innovators whose work builds on earlier innovations. Incentives to innovate are obtained by offering innovators the opportunity to profit from their innovations. Since innovations compete, awarding rights to one innovator reduces the value of the rights to prior...

We study a continuous-time version of the optimal risk-sharing problem with one-sided commitment. In the optimal contract, the agent's consumption is a time-invariant, strictly increasing function of a single state variable: the maximal level of the agent's income realized to date. We...

This article studies a tractable theoretical model of optimal consumption and saving decisions with endogenous retirement. Particular attention is paid to the impact of an increase in the risk of losing one’s job on the optimal path of consumption and wealth accumulation. Even if one does not...

Concealed earnings represent the largest source of fraud in the U.S. unemployment insurance system. Individuals with relatively low earnings constitute a larger fraction of those committing such fraud. High-earnings individuals, however, account for larger dollar amounts of this fraud.

In the U.S. unemployment insurance program, most of the overpayments due to fraud arise from individuals collecting benefits while they are gainfully employed. In addition, the overpayments are dwarfed by payments unclaimed by some who are eligible for unemployment benefits.

Not all who are eligible to receive unemployment benefits actually collect them.

Concealed Earnings fraud accounts for almost two-thirds of the total overpayments due to all fraud.

This paper presents a group of models showing the strikingly different implications of foreign aid to the private sector and public sector. In the first model, with decentralized decision-making and without optimal choices of fiscal policies on behalf of the government, foreign aid to the...