This paper considers a dynamic model of the evolution of open source software projects, focusing on the evolution of quality, contributing programmers, and users who contribute customer support to other users. Programmers who have used open source software are motivated by reciprocal altruism to...

Transplants of donated stem cells save the lives of many patients with blood diseases. Donation is somewhat painful, but rarely has lasting adverse effects. Patients can accept transplants only from donors with compatible immune systems. Those lacking a sibling match must seek donations from the...

Transplants of donated stem cells save the lives of many patients with blood diseases. Donation is somewhat painful, but rarely has lasting adverse effects. Patients can accept transplants only from donors with compatible immune systems. Those lacking a sibling match must seek donations from the...

Copyright affects the distribution of creative content. Taking works off copyright promotes their availability, which benefits consumers. But it also allows generic entry to dissipate producer surplus. This paper examines the effect of a copyright on the availability and price of books when...

Altruism or `regard for others' can encourage self-restraint among generators of negative externalities, thereby mitigating the externality problem. We explore how introducing impure altruism into standard regulatory settings alters regulatory prescriptions. We show that the optimal calibration...

We propose a model where voters experience an emotional cost when they observe a firm that has displayed insufficient concern for other people's welfare (altruism) in the process of making high profits. Even when there exist few truly altruistic firms, an equilibrium may emerge where all firms...

There are currently debates both about the ability to measure the value of moral sentiments and the nature of benefit-cost analysis. Moral sentiments can be reasonably measured in many situations and their consideration can improve benefit-cost analysis in any case. This argument is presented by...

Societies prohibit many transactions considered morally repugnant, although potentially efficiency-enhancing. We conducted an online choice experiment to characterize preferences for the morality and efficiency of payments to kidney donors. Preferences were heterogeneous, ranging from...

Societies prohibit many transactions considered morally repugnant, although potentially efficiency-enhancing. We conducted an online choice experiment to characterize preferences for the morality and efficiency of payments to kidney donors. Preferences were heterogeneous, ranging from...