[legitster]

> One way, often used regarding so-called food deserts, is to drop pins on the map representing consequential retail locations, draw a circle around them, and count who is and is not within one of the circles using census data. This is fairly naive and therefore is much beloved of social scientists, who can get grad students to do it for them.

> Some people in society have to actually be right about what they publish, and they have developed an important novel insight into human behavior: people cannot fly.

Haha savage.

I really love this article - it's a love letter to understanding all of the minutiae that goes behind something simple.

[tomjakubowski]

Patrick mocks the concept of "so-called food deserts", in part because social scientists use as-the-crow-flies distance to grocers to determine them, but compared to using road networks that is actually understating the problem of food access. (eg one might live one mile from a grocery store, but the walk would certainly cover more distance than that, and never less. not to mention lights slowing people down further...). So I'm not really sure what his burn is about.

[patio11]

I was introducing a jargon word that some readers would not be familiar with in an aside, so “so-called” is a flag to readers that food desert is a term of art they can look up if they want.

The comment is specifically that people who are not often considered intellectuals/researchers/etc, who have titles like Real Estate Acquisition Specialist, have a much higher fidelity understanding of the issue of access than the people society believe are largely the responsible voices regarding access issues.

This was in the context of an extended discussion about how e.g. regulators with an access mandate care about maps but that is insufficient.

[gammarator]

Fwiw to this reader it read as distracting snark and peripheral to your overall point.

Edit: if you simply wanted to flag “food desert” as a term of art, enclosing it in quotes would have been best. Your “so-called” implies that you are casting doubt on their existence.

[barry-cotter]

Well, they do exist, but they exist because the people who live in them don’t want to eat the approved kind of food. Far more a matter of demand than supply.

> Food Deserts and the Causes of Nutritional Inequality

> We study the causes of “nutritional inequality”: why the wealthy eat more healthfully than the poor in the United States. Exploiting supermarket entry, household moves to healthier neighborhoods, and purchasing patterns among households with identical local supply, we reject that neighborhood environments contribute meaningfully to nutritional inequality. Using a structural demand model, we find that exposing low-income households to the same products and prices available to high-income households reduces nutritional inequality by only nine percent, while the remaining 91 percent is driven by differences in demand. These findings counter the common notion that policies to reduce supply inequities, such as “food deserts,” could play an important role in reducing nutritional inequality. By contrast, the structural results predict that means-tested subsidies for healthy food could eliminate nutritional inequality at a fiscal cost of about 15 percent of the annual budget for the U.S. Supplemental Nutrition Assistance Program.

https://www.nber.org/papers/w24094

[secabeen]

Agreed. I also didn't see any useful connection as to how the information that the Real Estate Acquisition Specialists (REAS) have would actually generate more understanding of food access between different communities. Yes, the REAS for Stamford, CT is going to know a lot about access in Stamford, but almost nothing about access in Detroit, MI. Since the goal is to compare access across the country, using as-the-crow-flies data is preferred because it's universal and obtainable by a small research lab. The alternative is what, to interview a REAS from each of the 100 largest cities in the US, somehow convert their personal anecdotal knowledge into quantified data, and then use that to better understand access?

Expertise on a subject in one specific area doesn't necessarily translate to expertise in the general concept.

[patio11]

The REAS is local to the community. They work for the real estate developer, not for the HQ at the bank, which decided “We need 10 new branches in Chicago but eff if we know where they go; bring me proposals for corners you think you could get under contract.”

The reason they’re better at this than a professor is a bit controversial but I will own up to saying it: banks actually care about people using their branches and need to design systems which will correctly site those branches. Professors need to design systems which get their papers cited. Making accurate observations about reality is not necessarily required.

[secabeen]

Right, okay. I still think this is a bit of straw man. Professors don't generally claim to be an experts in local community access, so criticizing them for not being good at it doesn't help. Their focus is necessarily on publishing, and in making claims about access broadly that can be tested, or that can advance the field and be responded to, or cited.

"A grocery store on the corner of 24th and Main would help food access a lot and be quite successful" is not really a great research paper; but it is very useful to a business development person. "Food access is a significant problem in socioeconomically disadvantaged areas" is a fairly good research paper, but not something that you could ask the REAS in Community X to do for any area beyond Community X.

In the end, I think my question would be this. Let's take as true that Professors aren't all that accurate in their assessments of some issue, and that in their communities, REASs are more likely to be accurate in similar assessments. What then? How can we easily take that accurate, anecdotal REAS data, and turn it into broad comparative data that lets us better understand the problem nationwide?

[gammarator]

The bank of course has much greater incentive to get their siting estimate right—but it’s hard for me to see how the bank-local REAS feedback loop would work in practice. There’s no ability to test a counterfactual, and local branch performance only becomes apparent years after the siting decision, and with many confounders.

In contrast if the professor’s paper a) actually gets noticed and b) the study conclusions are actually sensitive to the details of the distance estimation methodology, there’s a possibility (not guarantee) of someone writing a rebuttal in six months, which is embarrassing. B is important—spherical cows are frequently good enough!

Fundamentally, we shouldn’t be surprised that the methods appropriate for “decide where to spend $20M on a building” and “spend <$100k of researcher time to perform population-level analysis” should differ.

[sedev]

Even if you're right — I don't think you are, but even if you are — you're derailing your own point to indulge in petty sniping targeted at another profession. The aside makes the piece weaker because it detracts from the focus and makes you sound like a jerk. If I were your editor, I'd have struck out the entire aside about social scientists and compressed it to "as is often the case, the naïve method has problems, so what banks do instead is…"

[tomjakubowski]

OK, I see that I read a little too much into that "so-called". Thanks for clarifying.

[Jill_the_Pill]

Also the term "food desert" is already being replaced by "food apartheid," which better highlights the structures and decisions behind the phenomenon.

[zmgsabst]

How does “food apartheid” better describe the situation?

[ceejayoz]

"Desert" implies force of nature. "Apartheid" implies human action.

[coredog64]

When I lived in Seattle, the nearest grocery store was a significantly shorter walk than drive thanks to the large park in the middle. Never say never, I guess.