This article investigates patent protection for a long sequence of innovations where firms repeatedly supersede each other. Incentives for R&D can be insufficient if successful firms earn market profit only until competitors achieve something better. To correct this problem, patents must provide...

This paper discusses the discounted utility (DU) model: its historical development, underlying assumptions, and "anomalies" - the empirical regularities that are inconsistent with its theoretical predictions. We then summarize the alternate theoretical formulations that have been advanced to...

The authors examine self-control problems--modeled as time-inconsistent, present-biased preferences--in a model where a person must do an activity exactly once. They emphasize two distinctions: do activities involve immediate costs or immediate rewards, and are people sophisticated or naive...

This paper investigates patent protection when there is a long sequence of innovations and firms repeatedly supersede each other. There can be insufficient incentives for R&D if successful firms earn market profit only until competitors achieve something better. To solve this problem, patents...

In active investment climates where firms sequentially improve each other's products, a patent can terminate either because it expires or because a non-infringing innovation displaces its product in the market. We define the length of time until one of these happens as the effective patent life,...

Recent models of procrastination due to self-control problems assume that a procrastinator considers just one option and is unaware of her self-control problems. We develop a model where a person chooses from a menu of options and is partially aware of her self-control problems. This menu model...