The empirical evidence of adverse selection in insurance markets is mixed. The problem in assessing the extent of adverse selection is that private information, on which agents act, is generally unobservable to the researcher, which makes it difficult to distinguish between adverse selection and...

Micro data from a dental insurance natural experiment is used to analyze why agents opt out of insurance. The purpose is to relate the dropout decision to new information on risk, acquired by the policy holder and the insurer. The results show that agents tend to leave the insurance when...

In this paper we derive tests for parameter constancy when the data generating process is non-stationary against the hypothesis that the parameters of the model change smoothly over time. To obtain the asymptotic distributions of the tests we generalize many theoretical results, as well as new...

This paper explores the profitability of portfolio-based momentum strategies. The data consists of all NYSE, AMEX, and NASDAQ stocks on the CRSP database. The analysis considers the period July 1963 to December 2002 and the tests are performed on portfolios formed on industry, size and...

We consider a leader and a subordinate he appoints who engage in team production. The public observes the organization's performance, but is unable to determine the separate contributions of the leader and of the subordinate. The leader may therefore claim credit for the good work of his...