Food Environment or Food Preferences?

“The public health literature has documented that lower income neighborhoods suffer from lower availability of healthy groceries and that lower-income households tend to eat less healthfully. In some circles, this relationship has been taken as causal, with significant policy attention devoted to improving access to healthy groceries in low-income neighborhoods.”

That's from a new paper by Hunt Allcott, Rebecca Diamond, Jean-Pierre Dubé.  This is one of the most rigorous investigations I've seen of the causal impacts of the "food environment" (in this case, the presence of grocery stores and movements of people into "healthier" neighborhoods) on dietary choice. 

What did they find?  From the conclusions:

“Entry of a new supermarket has a tightly estimated zero effect on healthy grocery purchases, and we can conclude that differential local access to supermarkets explains [no more] than about five percent of the difference in healthy eating between high- and low-income households. The data clearly show why this is the case: Americans travel a long way for shopping, so even households who live in “food deserts” with no supermarkets get most of their groceries from supermarkets. Entry of a new supermarket nearby therefore mostly diverts purchases from other supermarkets. This analysis reframes the discussion of food deserts in two ways. First, the entire notion of a “food desert” is misleading if it is based on a market definition that understates consumers’ willingness-to-travel. Second, any benefits of “combating food deserts” derive less from healthy eating and more from reducing travel costs.”

and

“we find that moving to an area where other people eat more or less healthfully does not affect households’ own healthy eating patterns, at least over the several year time horizon that the data allow. ”

The authors end by concluding that policy efforts to alter local food supplies are likely to be ineffective.  Their data strongly supports this conclusion.  They recommend, instead, to use public policy to improve health education.  I'm surprised they make this recommendation because their study provides no indication that more education would be a cost-effective intervention.  If anything, what their study shows is that economic development (turning low-income households into high-income households) is the most effective way to improve the healthiness of dietary choice.  

Hat tip to Alex Tabarrock at the Marginal Revolution blog who is highly skeptical of the food desert concept.  

Double Dipping?

With debates over the farm bill likely to heat up over the next year, it's interesting to see the lines of arguments coming out from different camps.  Today, the Environmental Working Group, an opponent of many farm subsidies, came out with a new publication.  They focus on what they call "double dipping", in which farmers receive payment when a loss occurs both from commodity programs (ARC or PLC) and from subsidized crop insurance programs.  

In their words:

“But farmers can – and hundreds of thousands do – participate in either ARC or PLC and in the crop insurance program. Most of the double dipping in the 2014 and 2015 growing seasons came from duplication of crop insurance and ARC payouts.

You don’t need a degree in agricultural economics to see the result: multiple payments going to the same farmers in the same counties to cover the same “drop” in revenue from crop sales. The interactive map below shows the counties where farmers received duplicate payments from at least two of the three programs.

In 2015, more than 2,300 counties received an ARC or PLC payment for losses incurred in 2014. Crop insurance policies paid out in more than three-fourths of those counties in 2014. The pattern was repeated the following year. ”

They created several maps illustrating where they argue "double-dipping" has most occured.

Over the last few farm bills, there seems to be less emphasis on traditional commodity programs and more focus on crop insurance.  To the extent arguments like this hold sway, I suspect that transition will continue.   

Food Flows

Last week I posted some crude calculations on how much states import and export various foods from other U.S. states.  Sandy Dall'erba from the University of Illinois alerted me to a dataset that gets at this question in a different way through records of interstate shipments (the FAF database from the Bureau of Transportation).  Sandy graciously agreed to let me share this figure he created based on these data.

You can read more about Sandy's work with Zhanglaing Chen here or contact Sandy to get a copy of their working paper "Drought, Interstate Trade and Agricultural Profit: Theory and Evidence" presented this year at the North American Regional Science Conference in Vancouver.

Inequalities of Fat Taxes and Thin Subsidies

I was excited to see The Economist ran an article on my paper with Laurent Muller, Anne Lacroix, and Bernard Ruffieux, which appeared in the Economic Journal.  In typical Economist fashion, they didn't mention us by name, but here's their summary of our findings:

“The study found that the taxes and subsidies actually widened health and fiscal inequalities. Fat taxes meant the women on lower incomes paid disproportionately more for food—their habits changed less. They preferred to buy food they liked rather than what made nutritional sense. Taxing the food they eat most made the poor poorer.

Subsidies encouraged all income groups to buy more fruit and vegetables. But those on higher incomes proved more responsive and so benefited most. Interestingly, richer folk were also more likely to buy the subsidised healthy food and then spend the savings they had accrued on yet more healthy food. But poorer women, if they responded to lower prices, often used the money saved to buy unhealthy items or something else entirely. Once the nutritional price policies were applied, the average share of budget spent on healthy food actually increased for the better-off. ”

Paarlberg on Farm Policy

Yesterday, I posted on a paper I wrote critiquing some of the proposals of the food movement.  As such, its probably only fair that I share a paper sent to me by a reader.  It was written by Don Paarlberg in 1987 and takes issue with farm policy from the Depression up to that date.  I found the history fascinating; the paper is short and well worth a read.  By the way, Don was a Professor of Agricultural Economics at Purdue and was a former Assistant Secretary of Agriculture.  

Here's an excerpt that shows some of the challenges with trying to manage agricultural prices and supplies.

“Some of the antics of the commodity programs are so ludicrous as to be almost unbelievable. Dairy programs are perhaps the most fantastic. The government supported the prices of dairy products with the intention of increasing dairy farm incomes. But, as every student who has taken a beginner’s course in economics knows, the result was to stimulate production, reduce consumption, and accumulate a surplus. The surplus of butter, cheese, and dried milk was then donated to those on the welfare rolls. This proved to be an inadequate outlet so then these products were donated overseas. The surplus was still growing so the government bought and slaughtered whole herds of dairy cattle. Thereupon the beef cattle producers, who are self-reliant and are not shielded by price supports or production controls, complained of this subsidized competition with their product and the government responded by purchasing beef for donation to the school lunch program. This did not adequately alleviate the complaints of the beef producers so the government exported beef from the slaughtered dairy herds, a strange action indeed since we suffer from beef shortages and import substantial amounts. Our forced exports of dairy beef disturbed other beef exporters, making an additional problem for the GATT multinational trade negotiations in Geneva. All of these questionable strategies were undertaken because the government was unwilling to follow the most simple and effective expedient: lowering the official price.

Meanwhile, those dairymen who stayed in business currently anticipate a reduced supply of milk and a better market. They are increasing their herds and laying the basis for a larger supply of milk. Like the sorcerer’s apprentice, they have heard the signal for delivering more water (in this case, milk) and have heard no credible signal for stopping. The commodity programs create surplus. They make a burden of what should be a blessing—our capability to produce food.”