The role of the priority rule in science

Science’s priority rule rewards those who are first to make a discovery, at the expense of all other scientists working towards the same goal, no matter how close they may be to making the same discovery. I propose an explanation of the priority rule that, better than previous explanations, accounts for the distinctive features of the rule. My explanation treats the priority system, and more generally, any scheme of rewards for scientific endeavor, as a device for achieving an allocation of resources among different research programs that provides as much benefit as possible to society. I show that the priority system is especially well suited to finding an efficient allocation of resources in those situations, characteristic of scientific inquiry, in which any success in an endeavor subsequent to the first success brings little additional benefit to society. 1. DISCOVERY AND PRIORITY Science aims to provide goods that all can share, but it does so in an atmosphere that is as competitive as it is cooperative. Consider what happens when several research programs all pursue the same scientific goal: there is a competition that has the form of a winner-takes-all race, that is, a race in which there are no second prizes. Remarkably enough, this is true in two quite distinct ways: first, with respect to the benefit that a successful research program confers on society, and second, with respect to the personal rewards—fame, prizes, authority, and so on—that accrue to the members of a successful research program. Let me say more about each. First, benefit to society. It is a consequence of the very nature of scientific information that, while the first of several competing research programs to achieve the programs’ common goal can expect to confer perhaps a great deal of benefit on society, the runners-up will confer very little or nothing. The reason is, of course, that additional discoveries of the same fact or procedure are pointless. Thus, whereas a typical economic goal, such as providing a swordfish steak or a back rub, can be realized over and over again to society’s benefit—we all have use for more than one meal or massage—the goal of a scientific research program needs to be realized just once for society to benefit maximally. Competing research programs are therefore racing to be the provider of a benefit in the knowledge that the first to achieve their common goal will, in reaching it, nullify the worth of the efforts of all the other competitors. Call this the benefits race. Second, personal benefit. Possibly the most distinctive feature of the social organization of science is the priority rule, the system of rewards which accords all credit, and so all the personal benefits that go along with credit, to the first research program to discover a particular fact or procedure, and none to other programs pursuing the same goal. As a consequence of the priority system, workers in competing research programs are involved in a