Marc F. Bellemare Posts

I am happy to share a leaner, meaner version of my paper with Jeff Bloem and Noah Wexler titled “The Paper of How: Estimating Treatment Effects with the Front-Door Criterion,” which we finished last week.

Here is the abstract:

We present the first application of Pearl’s (1995) front-door criterion to observational data wherein the required point-identification assumptions plausibly hold. For identification, the front-door criterion exploits exogenous mediator variables on the causal path. We estimate the effect of authorizing a shared Uber or Lyft ride on tipping by exploiting the plausibly exogenous variation in whether one actually shares a ride with a stranger conditional on authorizing sharing, on fare level, and on time-and-place fixed effects. We find that most of the observed negative effect on tipping is driven by selection. We then explore the consequences of violating the identification assumptions.

This version has benefited from comments from many people who were very generous with their time. We are grateful for any and all additional comments.

Today is the day after Labor Day in the US and Canada, which is the day the fall semester traditionally starts at the University of Minnesota.

Elsewhere in the northern hemisphere, universities have recently or soon will resume instruction, whether online or in person, which means that graduate programs in economics and related disciplines–agricultural and applied economics, business, political science, public policy, and so on–will be welcoming their new crop of graduate students.

Given the foregoing, I thought this was the ideal time to share a new working paper–a draft chapter from a forthcoming book–titled “How to Write Applied Papers in Economics.” This paper is meant to eliminate any guess-work in the paper-writing process for the new crop of graduate students as well as others.

That is the title of my most recently accepted article, coauthored with former Minnesota Applied Economics graduate student Vanee Dusoruth, and forthcoming in the COVID-19 special issue of Applied Economic Perspectives and Policy (AEPP).

Here is the abstract:

A few highly publicized food supply chain disruptions early in the COVID-19 pandemic were interpreted by some as evidence of a “broken” food system. One solution often brought in response to that perceived brokenness is urban agriculture. But the literature has sidestepped a key question: Who practices urban agriculture? Using survey data on 882 Montreal residents, we find that those who practice urban agriculture are more educated, and more likely to be homeowners and to report an income in the highest income bracket. This is consistent with urban agriculture being a luxury good.

And here is the paper. As the abstract indicates, this is a purely descriptive piece. I’d had the empirical results for it (and a draft of the paper) lying around for over five years, but I had never taken the time to polish the manuscript and do something with it. So when Craig Gundersen suggested we submit it to AEPP for its special issue on COVID-19, it was not difficult to make it fit.

One thing I love about this paper is that it illustrates the usefulness of publicly available data. The data we use come from the city of Montreal’s Open-Data Portal (ODP, in French here), which has data on a myriad of topics relevant to the city. One afternoon at work I was looking at what they had available, and I was surprised to see that the ODP had a whole “Agriculture and Food” topic area. I was even more surprise to find a survey of urban agricultural practices within the city, with clear documentation and a data set already cleaned.

Since you’re here, I should note that this is my first collaboration with a recording artist. Please check out my coauthor’s band Hallows here.