Category: Uncategorized

That’s the title of my latest article, coauthored with Dan Millimet, and which just came out in the spring issue of the Journal of Economic Perspectives. Here’s the abstract:

We discuss Yair Mundlak’s (1927–2015) contribution to econometrics through the lens of the fixed effects estimator. We set the stage by discussing Mundlak’s life and his seminal 1961 article in the Journal of Farm Economics, showing how it was looking at the right application—the study of agricultural productivity, which had hitherto been thought to be marred by the presence of management bias—that led Mundlak to use the fixed effects estimator. After discussing Mundlak’s contribution, we briefly discuss the historical economic and statistical contexts in which he made that contribution. We then highlight the dialogue that took place between the proponents of fixed versus random effects and discuss how Mundlak settled the debate in his 1978 Econometrica article. We conclude by discussing how, between fixed and random effects, the fixed effects estimator won the day, becoming the de facto estimator of choice among applied economists because of the Credibility Revolution, culminating in the popularity nowadays of difference-in-differences designs and of two-way fixed effects estimators.

I have learned a lot while working on this article. Like many people, I thought Mundlak himself had developed the fixed effects estimator. But that turned out not to be true: The estimator was already available; what Mundlak did which forever associated his name with the fixed effects estimator was to find the right application for it. Having recently published an article in which my coauthors and I present the first application of an estimator to economics, this was very encouraging.

As a result of having served as editor of Food Policy (2015-2019) and the American Journal of Agricultural Economics (2019-2023), I’ve been asked to write a lot of tenure and promotion letters these past ten years. This has given me a chance to reflect on how people can be successful in agricultural economics. Given that, I thought I should uncover some of the hidden curriculum behind how people’s research portfolios are evaluated on the job market, for tenure, for promotion, and so on.

But first, what does “successful” mean? This is where objective criteria come into play, but I can think of several proxies for success.¹ First, there is success at the extensive margin: Does someone get tenure? Do they get promoted? Are they considered for endowed chairs or named professorships? Second, there is success at the intensive margin: How many Google Scholar or Web of Science citations does someone have? What is their h-index? What is their salary relative to comparable matches? And then there is stuff like the kind of job offers they get when they go on the market.

“Quantity has a quality all of its own,” a mentor once told me. By that, he was alluding to the fact that while some researchers in our discipline (i.e., agricultural economics) are known for publishing high-quality articles, others are known for publishing a high quantity of articles, and that publishing a high quantity of articles can eventually add up to quality. I wanted to talk about quantity, quality, or even both can be leveraged in terms of having a scholarly impact.

I have received a lot of positive feedback on my first two posts of the year (see here on how development economics has seemingly become about anything and everything, and see here on whether agricultural economics departments should invest further in international development). People seem to be enjoying the longer-form thoughts I share here about the fields I have worked in and, in the process, about the economics profession more broadly.

My interest in writing these posts goes back to my first year of college, when I took two classes which have profoundly influenced my thinking—one on the philosophy of knowledge, one on the analysis of scientific discourse—when doing a minor in philosophy.

I spent part of last summer working on a forthcoming article with Dan Millimet on Yair Mundlak and the fixed effects estimator. While working on that article, I was reminded of how the Agricultural and Applied Economics Association (AAEA, my professional home) used to be known as the American Agricultural Economics Association (it was known by that name when I attende my first AAEA annual meeting in 2003) and how, before that, it had been known as the American Farm Economics Association.¹

Note the change in focus: From farm economics to agricultural economics, and from agricultural economics to agricultural and applied economics.

This emphasis on “applied economics” and whether it remains relevant is the subject of this post.