Having been tenured now for almost 28 years, I have been in many promotion meetings. There is a little dance that happens in a large fraction of these meetings. Someone raises the issue of whether one or more of the papers of the one being evaluated owed more to a coauthor than to the evaluee. Then, this concern is dismissed by invocation of the idea that there is a reasonably efficient market for coauthors. Those who contribute less than their share to a project are much less likely to be invited to be a coauthor a second time. I think this dismissal of the concern is right.

There is a key economic force at work in the market for coauthors in economics that is important for other economic applications as well. When a wage is fixed, the quality of the worker hired or the effort put in by the worker hired adjusts to bring the marginal product closer to the fixed wage. (Thus, for example, when an increase in the minimum wage pushes the wage up, increased worker effort per hour for fear of losing that now more attractive job, or a better class of worker can make up for a fair share of the strain on the firm from that higher wage.)

Some naively think that the most famous economist on a paper contributed more to it. But those with a little more experience now that the less famous coauthor usually has put in a lot more hours into the paper, tending to equalize the overall contribution even when the more famous coauthor is able to contribute more to the paper per hour expended.

As someone who has more ideas than I could possibly fully realize by myself, I get very annoyed at the idea that people would fail to give my coauthors equal credit for papers. If I can’t offer coauthors equal credit for papers, how can I get the help I need to realize those ideas? I, for one, appreciate that ideas by themselves are not published papers. It takes a lot to get from an idea to a paper ready to submit. And in economics it takes almost as effort to take a paper from first submission to acceptance and final publication.

It is wrongheaded to think that idea creation should get most of the credit. Many people have no picture of how many good ideas languish inside some economist’s head or in the space of casual conversation and never make their way into a published paper. Let me oversimplify: idea people and those who can execute on an idea need each other. A system that gives each of them ample credit can work well to help foster good matches and an efficient allocation of tasks within the coauthoring partnership.

I’m not saying that the systems of giving credit in other disciplines are a bad idea. They may also work. But given the “fixed wage” of equal credit for coauthors on a paper in economics, who is chosen as a coauthor and how much they are expected to do adjusts to make equal credit a good approximation on average, even when focusing on pairings between senior and junior coauthors.

Update, May 22, 2021: Michael Harris points to the paper “First Author Conditions,” which has this abstract:

This paper provides a theoretical explanation for the persistent use of alphabetical name ordering on academic papers in economics. In a context in which market participants are interested in evaluating the relative individual contribution of authors, it is an equilibrium for papers to use alphabetical ordering. Moreover, it is never an equilibrium for authors always to be listed in order of relative contribution. In fact, we show via an example that the alphabetical name ordering norm may be the unique equilibrium, althoug multiple equilibria are also possible. Finally, we charaterize the welfare properties of the noncooperative equilibrium and show it to produce research of lower quality than is optimal and than would be achieved if coauthors were forced to use name ordering to signal relative contribution.

Don’t miss my related post:

• When Women Don’t Get Any Credit for Coauthoring with Men