Dry Holes in Economic Research: Reply
回应Mayer的评论，重申对经济学研究社会效率的质疑，指出尽管高被引论文数量增加，但社会投资回报率仍难为正。
As Mayer (2004) recognizes, our paper refers generally to the optimal rate of scientific exploration and specifically to what seems to us to be little evidence of socially efficient investment, at least with respect to economics. We do not claim to know, or care to argue about, the optimal incidence of scientific papers that no one uses in subsequent research. In our opinion, Mayer’s focus on the technical issues he raises, with which we have no quarrel, suggests that he may be missing the forest for the trees. Even admitting that more good (and many more bad) papers are being produced now, relative to a generation ago, it is very difficult to argue that the social rate of return is positive. Consider our case in terms of the numbers of highly-cited papers (rather than the percentage of never-cited papers). The stock of existing literature is growing exponentially over time, which means that the universe of citable literature is expanding rapidly. Compounded with the increasing tendency to cite others, as noted by Mayer (Ellison 2002), this means that, on average, those papers that are cited ought to attract more citations now than 25 years ago, ceteris paribus. This is borne out by the evidence, taken from Table 2 of our original paper. In 1974, there were 11 papers published (0.55 percent of the papers in that year’s sample) that attracted more than 40 citations in the following 5 years. In 1996, there were 43 papers (1.16 percent of the papers in that year’s sample) that attracted more than 40 citations in the 5 years immediately following publication. Now comes the tricky part – interpretation. Has the massive implicit social investment in academic research that we discussed in our original paper been justified in terms of producing 32 more papers with this level of citations? Although we looked at only 2 years, let’s suppose that we are producing an additional 32 papers per year with that level of citation. Is this payoff worth the investment? Let’s pick a different threshold for judging ‘important’