Why are some economists remarkably productive?
A short answer to your question is both yes and no. You have to first define productivity: productivity, in my opinion, cannot simply mean publishing the number of articles, but rather, their impact. A typical way of modelling the impact of authors is by looking at their h-index. There are many other ways of measuring productivity as well- where the articles are published is important as well. The top 5 journals in economics are (in no particular order): Econometrica, AER, QJE, JPE and ReStud. Articles published in these journals are generally of high quality. However, there are many articles that are published in these journals that do not always have the desired impact. Many a time, articles ranked in lower journals have a high impact. Consequently, it is extremely difficult to measure productivity. To me, the h-index is a good measure.