GAREY C. DURDEN AND TIMOTHY J. PERRI* This study extends a recent paper by Jean Louis Heck and Peter A. Zaleski  on trends in economics journal publication from 1969-89. The primary purpose of the work is to analyze the impact on article production of an observed dramatically increasing tendency toward coauthorship among scholars in economics. A simple model is tested with total (per capita) articles as a function of time, American Economic Association (AEA) membership, and articles coauthored per year. Results suggest that the increasing trend toward coauthorship enhances productivity in total and per-capita article production (JEL A14).
I. Introduction Several papers have investigated certain aspects of the recent trend toward proportionally increasing coauthorship among economists. Heck and Zaleski  used an aggregated data set compiled from the Journal o f Economic Literature and examined the 1969-89 time period finding, among other things, that coauthorship has increased from about 15.1 percent of total papers listed in 1969 to 35.7 percent of those listed in the JEL in 1989. Using citation counts to isolate important articles published in the American Economic Review between 1965-85, Sophocleus  reported that coauthorship over the period increased from 29.4 percent to 52.8 percent of the total articles published. Barnett, Ault, and Kaserman  collected a sample of 2,535 papers from the AER over the same 1960-85 period and successfully estimated the determinants of total authors per article. McDowell and Melvin  also modeled and tested the determinants of coauthorship, and Sauer  has estimated the academic returns to coauthorship. McDowell and Smith  investigated the phenomenon of gender sorting among coauthors (men more often work with men and the converse) and found evidence that this practice may decrease productivity among women as compared with men. The problem arises because there are far fewer coauthorship opportunities for women due to their relatively small numbers, especially in smaller schools. Although some of the studies cited do present and develop the notion that coauthorship among economists enhances productivity, very little formal work has been done to model and test this hypothesis. 1 The purpose of this paper is to develop and test a simple model of the effect of coauthorship on article production and test the model using data (summarized in Table 1) from Heck and Zaleski .
*The authors would like to thank Gary Shelley, Janet K. Smith, Peter Zaleski, and an anonymousreferee for comments on previous versions of this paper. 1One exception is found in McDowell and Smith . They used a cohort sample of 89 men and 89 women receiving Ph.D.s between 1968-75. In a sub-sample of 106 persons, they found no evidence that coauthorship increased the number of articles per scholar when total articles were discountedby the number of coauthors.
AEJ: MARCH 1995, VOL. 23, NO. 1
Section 2 of this paper provides a discussion of the underlying reasons for increasing coauthorship and provides intuitive reasoning as to why coauthorship should increase article production. The model is developed in section 3 and the empirical results discussed in section 4. A summary and some conclusions are presented in section 5.
II. Coauthorship as a Basis for Increasing Article Production
Most authors will want to publish individually in order to demonstrate this capability to those who make recommendations for promotion, tenure, and salary increases. Singleauthored publications may also be important, at the margin, for the enhancement of mobility. There is little doubt, however, that the growing "publish or perish" requirement plays a major role in the observed proportional increase in coauthorship. This contention is enhanced by the fact that schools not formerly research-oriented at all (e.g., many of those