They destroyed huge amounts of food again

Every year or so, another huge food recall makes the news, and it makes me sad.

The latest is the recall of 200 million eggs (link) due to salmonella "risk."

The identification of the cause of such disease outbreaks is a great case study of causal investigations, which I cover in detail in my book, Numbers Rule Your World. In that section, I also raise questions about the (in)sanity of these broad-based food recalls.

How does a food recall save a life?

All of the following have to happen:

• Some proportion of the recalled eggs has to be contaminated
• The contaminated eggs have to be purchased by consumers
• The contaminated eggs have not already been consumed or discarded before the recall (while the investigation was happening. From this epi curve, it looks like the greatest concentration of reported cases occurred in Nov/Dec 2017, four months ago.)
• Those who bought the eggs learn of the outbreak and subsequent recall
• Those who knew of the recall take action to return or dispose of their eggs
• Someone would have eaten those tainted eggs if they weren't recalled
• When eating the tainted eggs, the consumers do not cook them thoroughly
• The immune systems of those people who ate the tainted eggs fail to fight off the illness on their own
• The sick person decides to go to a hospital, thus identifying him/herself to CDC
• The sick person does not recover, typically due to having some pre-existing conditions that weakens his/her defence

The short version: the saved life has to be someone who would have died from consuming the tainted eggs were they not subject to this massive recall.

Each one of the above steps happen with some level of probability. For all these steps to happen at the same time is highly unlikely.

The economic fallout of dumping all those eggs is certain. The benefit of the recall in human lives is highly uncertain. So, it's not clear to me that these recalls are reasonable.

 

Comments

[Glen DePalma]

Does the recall help in protecting against potential future lawsuits?

[Adam Schwartz]

Or building on Glen's comment... could recalls act as an effective deterrent against future bad behavior? It's not so much about this case - as you point out the risk could be quite low. But if all food producers experienced little to no recourse for poor hygiene would the negative effects be direct enough and traceable enough that free-market economics could effectively punish those behaving badly?

BTW, reporting to the CDC isn't necessary to save a life - it's only necessary to the extent it helps measure the impact of a salmonella outbreak. Second, death isn't the only possible downside of getting food poisoning - there's also the cost to the individual of lost work, otherwise unnecessary dr. visits, etc. And lastly, cross contamination is a potential problem - even if the contaminated eggs were cooked properly.

I do agree that 4 months after the outbreak seems a bit late to be treating the problem, but then I know little of how long eggs take to work their way through the system - they certainly seem to stay good in my fridge for a long time.

[Kaiser]

GD: We'd have to consult a lawyer. I'm supposing that only a small proportion of the 200 million eggs will be returned, especially those that have reached homes. Does announcing a recall protect one against future lawsuits? I'm not sure.

AS raises many interesting issues. Firstly, given that the salmonella has been traced back to that particular supplier, it would seem like the first best deterrent is a penalty for this supplier causing this incident. Secondly, it does take months and a lot of work to find the source of contamination - a process that I cover in detail in my book, so pretty much every time a recall is announced, it happens months after the peak of the contamination.

Also, while reporting to CDC isn't needed to "save a life", it is needed for the counterfactual.

[Glen DePalma]

One more point:

Companies do not recall products ONLY for saving lives. The potential economic loss of the companies had they not recalled the foods and the media found out that the companies knew about it is huge.

When a company recalls its product, in a weird way it gains more trust from the customers.