This paper is no longer available on-line from the NBER. A revised version of the paper has been published as "Diversification Across Time" in the Journal of Portfolio Management 39 (Winter 2013), pp.73-86

John Lott and David Mustard have used regression analysis to argue forcefully that 'shall-issue' laws (which give citizens an unimpeded right to secure permits for concealed weapons) reduce violent crime. While certain facially plausible statistical models appear to generate this conclusion,...

Private expenditures on crime reduction have potentially important externalities. Observable measures such as barbed-wire fences and deadbolt locks may shift crime to those who are unprotected, imposing a negative externality. Unobservable precautions, on the other hand, may provide positive...

Kaplow and Shavell have recently claimed that property rules tend to protect tangible entitlements more efficiently than do liability rules. They argue that while liability rules tend to efficiently harness the defendant's private information when courts are imperfectly informed as to litigants'...

The central allocative decision confronting a judge in a nuisance dispute should not concern the identity of the initial entitlement recipient but rather the identity of the more efficient chooserthe litigant who can more efficiently allocate the entitlement. We show that liability rules can...

We study option management by committee. Analysis is illustrated by tenure decisions. Our innovations are two-fold: we treat the committee's problem as one of social choice, not of information aggregation; and we endogenise the outside option: rejecting a candidate at either the probationary or...

We study option management by committee. Analysis is illustrated by tenure decisions. Our innovations are two-fold: we treat the committee's problem as one of social choice, not information aggregation; and we endogenise the outside option: rejecting a candidate at either the probationary or...