Lessons of the Listeria Outbreak: Do Locavores Make Us Less Safe?

As the death toll from listeria in cantaloupe reached 25 this week, marking the deadliest outbreak of foodborne illness in a quarter-century, some industry insiders are placing blame on the local foods movement. On economic grounds, they may have a point.

The contaminated melons were traced to a self-described small farm in Colorado that the FDA said had “poor sanitary” conditions. The FDA reported Wednesday that it found listeria in numerous areas of the farm’s packing facility, including a floor drain, a produce dryer, and a conveyor belt. Standing water and poorly designed equipment created “the perfect environment for listeria growth and spread,” according to one FDA expert. The farm claimed to have passed an outside audit just days before the outbreak that has sickened more than 100 people and devastated the cantaloupe industry. Farmers in California are plowing their crops under because of the collapse in demand.

That the outbreak occurred on a small farm selling principally to regional buyers is an obvious point, but also an important one because this kind of food contamination is less likely to occur at the large-scale farming operations that locavores love to hate. Consider first that local food systems largely ignore the important role comparative advantage plays in agriculture. Comparative advantage explains why corn is grown in Iowa, almonds in California, and winter vegetables in Florida. The different regions, with different soils, land qualities, climates, and opportunity costs specialize because they can produce their respective crops better than other regions. Comparative advantage implies significant gains from interregional and international trade. And it isn’t just relevant to costs of production and farm yields. It applies also to food safety.

Some regions are just safer places to grow certain crops than others—a point made recently by long-time food industry observer Jim Prevor at his “Perishable Pundit” website. Colorado, he notes, is a particularly unsafe place to grow cantaloupes, which are particularly susceptible to contamination because bacteria can hide out in the crevices of the melon’s rough skin. Rains splatter mud on the melons in Colorado, requiring them to be washed post harvest, a process that can lead to cross contamination among melons and create the moist conditions in which bacteria thrive.

In contrast, dry summers in California and Arizona create safe conditions for cantaloupe production because the crops are watered by drip irrigation and are much less likely to get dirty. Consequently, California cantaloupes bypass the rinsing phase and are packaged dry, sometimes right in the field. But the local foods movement kicks comparative advantage to the curb, favoring foods grown within a certain distance over foods grown in the best conditions.

The small farm is also likely to invest less in preventing food contamination than the big farm because its losses and legal exposure from any outbreak will be smaller. Even if the contaminated farm in Colorado grew half of the state’s 2,200 acres of cantaloupe, its loss from pulling its harvest is only $4 million in revenues. (The total U.S. harvest in 2010 was valued at $314 million.)

A larger farm has much more at stake, both in terms of lost harvest revenues and reputation. Reputation is critical to firms in the food industry as health scares can dramatically reduce demand well into the future. To large firms in the industry, an outbreak can mean hundreds of millions of dollars in foregone sales and liability. This creates a big incentive for these firms to invest in equipment, procedures, and testing to minimize the risk of food contamination at farms and packing sheds. Further, geographic concentration of production allows farms to work jointly and cooperatively to achieve food safety for their mutual protection.

It’s not just that the benefit of food safety investments (i.e., avoided losses) is lower for small farms. Their costs of achieving a given level of risk are often higher, too. Large firms exploit economies of size to achieve food safety standards more cheaply than small firms. A simple example is fencing a field to avoid animal intrusions and fecal contamination. The cost of fencing per unit area is decreasing in the size of the field. At $10 per foot, it costs $4000 to fence a 10,000 square-foot field. The cost of fencing a field 100 percent larger is only $5,650*, less than 50 percent more.

More generally, because of the fixed costs associated with prevention efforts, large firms have an advantage in mitigating against food contamination. They can spread the costs of equipment and personnel over larger quantities of output to lower their average costs. Thus it is no surprise that research by economists at UC Davis, and the USDA found that large food operations have lower costs for complying with food safety standards and are more likely to invest in equipment and pathogen testing to reduce contamination risk. Large firms also often hire food safety specialists to oversee food safety protocols and testing for contamination.

Because the costs of achieving low levels of contamination risk are so high for small farms, they were exempted from stricter food safety standards required by Food Safety Modernization Act signed by President Obama earlier this year. The act calls for the USDA to issue tighter standards for preventive measures and testing on farms and elsewhere in the food supply chain.

Food-safety costs are also greater for the taxpayer when dealing with small-scale, geographically scattered farming. The cost of monitoring regulatory compliance is smaller the fewer and more concentrated the farms become. In the locavore utopia, federal inspectors would have to travel to hundreds of local food sheds and inspect dozens, perhaps hundreds, of farms in each one. As the number of commercial farms increases, either the costs of labor and transportation associated with inspection go up, or the compliance level falls. The local foods movement, then, makes it more costly for the government to assure the food supply is safe.

Finally, assuming small farms are not inherently safer than large farms, then as food retailers endeavor to meet the demands of locavores by sourcing meats and produce from local farms, they must compromise on other priorities, like reducing contamination risk. Food retailers have many objectives in securing produce from suppliers, including minimizing cost and maximizing flavor. The many potentially conflicting objectives impede the retailer’s ability to achieve any one objective to the greatest degree possible. The retailer faces tradeoffs. Sourcing local food from smaller farms that are less effective in mitigating contamination risk almost surely comes at the cost of food safety, a point also m
ade by Mr. Prevor.

The recent listeria outbreak highlights the risk posed by accidental food contamination to consumers and farmers alike. Twenty-five dead. Hundreds sick. And millions of dollars of cantaloupe plowed into the ground. It’s a painful reminder of how much we rely on a safe and secure food system. And it is worth asking if a local food future will put us at greater risk.

*An earlier version incorrectly read, “At $10 per foot, it costs $4000 to fence a 1000 square-foot field. The cost of fencing a field 100 percent larger is only $6,000, a mere 50 percent more.”

Mary Schaad

Mr. Sexton: your argument here has been intelligently discredited by Mother Jones, which has done well to point out the mistakes with which your blog post is fraught. A farm in Colorado whose produce is reaching and killing consumers all over the country is not part of the locavore movement. You seem to be grossly ignorant of the definition of a "local food system."



I take issue with your use of "small" to describe this farm. Jensen Farms distributes far and wide in the United States, otherwise they wouldn't have been able to distribute tainted cantaloupe to 18 states. They also sell their products at Safeway, WalMart, and Sam's Club. Since when did "small farms" produce enough to distribute to such retail giants?

Perhaps rather than talking to "industry insiders" or taking a company's word for their status as a "small farm" you should dig a little deeper.

H E Shoup

I loved your books! I even bought the audio CDs so I could listen to them in the car. However, you missed the boat here, which now makes me wonder if you took such liberties with your conclusions in your books. I just read Tom Philpott's article in Mother Jones - I hope you'll reconsider your conclusions and regain your credibility.


Jensen Farms is by no means a small farm. For fresh produce, once you get above about 50 acres or so you are medium sized, at 500 you are large and over 2500 acres you are a giant. Even then, it all depends on what you are growing. Generally speaking the small grower has a more face to face relationship with the people that eat their food and worry more about potentially killing people than some large multi-million dollar corporation.


I can't believe this farm is actually being considered small by anyone. A 480-acre operation capable of shipping its product to 26 states is by no definition, a small farm. Small farms are characterized by the variety of crops they grow and by the local consumers they supply. Monocultural farms that ship across the country are members of the modern, industrialized farming community, and this listeria outbreak is just more proof that modern ag is failing consumers.

Anne Armistead

Your definition of a local small farm does not meet my definition. Since moving to a small town filled with local farms and local CSA's and farm markets my health has thrived using good nutrition instead of big pharma and no one here is getting sick we are all getting healthy. You write like someone who favors large food operations which I believe are unhealthy for us all. I refer your readers to this article http://motherjones.com/tom-philpott/2011/10/freakonomics-cantaloupes-listeria I wish my taxes would STOP subsidizing greedy big AG and start subsisidizing the small farms that enhance my quality of life with REAL food that is not GMO and/or contaminated with loads of horrible pesticides. BIG AG is always trying to scare people in an attempt to get rid of local small farms which the majority of us prefer. If you live in a city start gardening and join forces with your neighbors so you too can have quality food where you live...



So, you're point rests on the fallacy that Jenson Farms is a small farm. Clearly, if they were shipping fruit all across the country that really don't hold up. This was, in every way, industrial food, a perfect example of why buying produce from small local farms makes sense. I'm not sure why you have the need to take down small farms, but this incident really has nothing to do with them.



You idiots should stick to writing about what you know. Of course that means you would write about nothing.


I have serious issues with a recent post on their website.
In the posted article, Steve Sexton uses the recent cantaloupe-triggered listeriosis outbreak to argue that a local food economy based on small-scale farming is less safe than a large industrial-scale system.
Several of his points did not hold water, in my opinion, and I will start with the boring nit-picky ones.
He brought up the problem of inspecting many small farms, writing, “In the locavore utopia, federal inspectors would have to travel to hundreds of local food sheds and inspect dozens, perhaps hundreds, of farms in each one.”
If this “locavore utopia” were to exist, official inspections would become unnecessary, as the consumers themselves would be able to inspect the farms. They would live close by, and would probably be going there anyway from time to time to pick up food. There would be constant scrutiny from multiple customers, rather than one visit from an official.
Sexton says that small farms, because they make fewer sales, have less to lose from outbreaks, both in damage to reputation and monetarily, and suggests that the up to $4 million that the Colorado cantaloupe farm might lose is not enough of an incentive to enact stringent safety requirements. I do not know any small farmers who scoff at $4 million. Sexton does not explain why loss of reputability would be problematic for large but not for small farms.
Another argument made in the article is that this incident shows that it is dangerous to grow fruit or vegetable varieties in any geographical area that they are not perfectly adapted to, so therefore cantaloupes should be shipped in from giant mega-farms in California or Arizona. An FDA report on the listeriosis outbreak does not support this argument, as it found that, “All environmental samples collected in the growing fields were negative for Listeria monocytogenes,” making it much more likely that contamination of the melons occurred not while growing in the field, but later, in the packing facility, from packing equipment or a dirty conveyor belt.
Wait a minute. Conveyor belt? Packing facility? This doesn’t sound like a small farm.
It isn’t, and this is the main problem with Sexton’s article. Jensen Farms, the “small farm” where the contaminated countaloupes originated, produces 300,000 cases of cantaloupe on 480 acres.
I have purchased produce from eight or ten farms at the Bowling Green farmer’s market, and I can tell you that all of these farms put together don’t amount to 480 acres, and that is including the 330 acre Riehm Farm. Most are less than 10 acres. 10 acres should be enough to employ at least 6 people and feed at least 3000.
Jensen Farms in fact almost completely fails to represent the kind of farm that a locavore would endorse. It distributes far and wide, to 26 different states.
9 out of 10 locavores will tell you that lack of variety is a problem with the industrial-scale food system. Jensen Farms only grows three crops, the vast majority being cantaloupes. Compare that to Riehm Farm. They boast that for every letter of the alphabet, they grow at least one fruit or vegetable that starts with that letter.
The same FDA report mentioned earlier cites the storage and refrigeration methods as a possible contributor to the growth of Listeria. In a “locavore utopia” fruits and vegetables would be eaten fresh, without significant storage time, and almost certainly without refrigeration.
Don’t be afraid of local food from small farms. The “locavore utopia” mentioned in the Freakonomics website post will have almost nothing in common with the cantaloupe farm at ground zero of the listeriosis outbreak.
A food poisoning outbreak in a “locavore utopia” would be easily traceable to the farm from which the produce was directly purchased. Instead of there being a ripple effect as is the case now, where everyone is afraid to buy any cantaloupe from anywhere, it would be the produce from one small farm that would be avoided.



Why Freakonomics Is Wrong About Cantaloupes


A "small farm"? Because they describe themselves as a small farm that makes them one? Your base premise is flawed - this is not a small farm.

"Regional distribution"? Because they "only" shipped to 26 states, this is regional? It would have had to be world-wide to not be regional? Another serious flaw in your argument.

The listeria - yes, it probably came from the cows. Cows likely fed silage, on a large farm.

It's amusing that you had to distort the story so much, to come to your conclusion.


This was not some little local farm selling melons at the farmers' market. People were harmed in over half the county. It is agribusiness on a big scale. Maybe not as big as Cargill, say, which has had its own contamination problems of late, but big nonetheless. There is no basis at all for the theory that the bigger the industrial farm, the safer it is. I will continue to buy my produce from local organic farms run by people I know and trust to respect the customer. Nobody has been poisoned by the local farmers; it's the big guys who are only looking at the bottom line.

jim collins

Exactly how is a farm that "ships 1.5 million cantaloupes to 24 states" Locavore? They are an industrial farm that failed to follow basic safety precautions such as chlorinated water and controlled cooling followed by everyone else.


The author very clearly has no idea of how agriculture or agricultural communities work in eastern Colorado - these are pivot-irrigated crops, as eastern CO is a very dry place and "rains" don't "splatter mud" on the skin, at least not around the harvest time, when there's essentially no rain in eastern CO. These "small farms" (which as near as I can tell are big enough to largely use industrial agricultural methods) are actually of large enough size to supply to the likes of Safeway and Wal Mart as well as local farmers markets. They also clearly have a lot at stake in terms of reputation - the entire town of Rocky Ford markets itself as a high-quality cantaloupe producer, with ads on the radio, newspaper, etc. when cantaloupes are in season. In rural eastern Colorado, which can get pretty economically depressed, having anything a town can claim to keep it afloat socially and economically means something. So clearly these folks have reputation to uphold (as does any small
farm competing for customers at a farmers market), though they also have "geographic concentration of production allowing farms to work jointly and cooperatively to achieve food safety for their mutual protection", and probably stronger social connections between small and medium sized farms to work jointly together than megafarms.

But I guess industrial-scale farms never have food safety issues, so it's just a small-farm problem.



Perhaps food that suits the area is the food that should be grown? I life in the tropics and I'm certainly not growing cold climate produce in my garden... why would we expect farms to be any different.

We should adapt to our local climate and available resources for food. So I eat the food that is available locally, from local suppliers.

If I want to eat cold climate food, I should move to a cold climate.


Who's paying you? Which big company is wanting to taint people who just want to be sufficient and have a little soul in their lives?

Just wondering.......

These posts on locavores are most pointed. Listeria happens in processed food too, and it can be argued that if affects more people. Your arguments are missing something.

(The viewpoint from the other side :)


I work at a Farmers Market where I see struggling local farmers sell their products every day. These farmers are my friends and coworkers and I trust their product and admire their work. The outbreak clearly affected hundreds of people and it is terribly sad, but you cannot condemn all local farmers because of one farmer’s mistakes. The first thing that stood out to me in this article is the statement, “The farm passed audit just days before the outbreak”. Why was the firm allowed to pass an inspection? Clearly the Listeria did not pop up overnight. Yes farming costs a great deal of money and it is incredibly expensive and even more expensive for small farms, because they do not have the backing of a huge commercial farm. It is like comparing me losing one hundred dollars and Bill Gates losing one hundred dollars; obviously there is a big difference here. Local farms are good for the local economy. You should not be able to get a watermelon in the winter in a cold environment; it is seasonal and that is why when summer rolls around we go to Pungo and pick strawberries. While I value the opinion of Mr. Sexton I also know and have seen first-hand the hard work these people put into their products and they should not be condemned for one farm producing a bad product, but perhaps someone should ask the FDA why they must do to pass an inspection because clearly it is too easy.



Give migrant workers toilets so they don't poop in the fields and you won't have to worry about what splashes on the melons when it rains.