I told my friend Mike I was thinking of trading my car in for one that used less gas. Nowadays I would talk about the Market for Lemons as a reason against doing what I was thinking of doing. But in 1974 I didn't know about Akerlof's famous paper, and neither did Mike, who was majoring in music. "Better to stick with the devil you know" he said.
"The Devil you know" and "the Market for Lemons" are similar: both use asymmetric information (the seller knows more about the car than the prospective buyer) to explain a low volume of trade. But they are not the same. A thought-experiment can explain the difference.
Suppose the government made a surprise announcement: everybody who owns a used car must sell it next week to the highest bidder. If you still want a car you must sell yours and buy someone else's.
Making sales compulsory solves the Market for Lemons problem. The sample of cars offered for sale represents the whole population of cars; those who know their own car is a cream puff can't hold it back from the market. If the Market for Lemons was the only problem in the used car market, then the compulsory universal sale would improve efficiency in the allocation of cars. People who found themselves needing to drive more miles could sell their gas guzzlers to the people who found themselves driving fewer miles.
But universal compulsory sales of cars does not solve the Devil You Know problem.
First there's simple risk aversion. Suppose everyone knows that half the cars need a $1,000 repair and the other half don't, but only the seller knows if his own car needs that repair. Sellers of lemons have a 50% chance of winning $1,000, which is worth less than a certain $500 if they are risk-averse. Sellers of cream puffs know they have a 50% chance of losing $1,000, which is worth more than a certain $500 loss if they are risk-averse. (Remember that everyone buys a car for the same price they sell their car, so price is a wash, if this is the only difference.) The value of the expected gains to the expected gainers are worth less than the value of the expected losses to the expected losers.
Second, even if everyone is risk-neutral, there's the problem of not knowing what particular repairs are needed. If your car needs to have the brake pads replaced soon, it's better to know that fact before they wear down too much and you need to replace the rotors too (or worse). And if your car won't start on a cold morning, or overheats on hot days, it's better to know that fact in advance, so you can plan accordingly.
[And if the government's surprise announcement is not a surprise, but is announced well in advance, there's an additional problem. Nobody will change the oil if they know they are going to sell the car anyway. But that's the standard Moral Hazard problem, which is distinct from the Devil You Know problem.]
I wonder which problem matters more, in the used car market. Or in finance?
I started to think about the Devil You Know when thinking about the choice of textbook for Intro Economics. You never really know the flaws in a textbook until you have taught from it. Changing textbooks is always risky; and the flaws catch the teacher unprepared. Most of our switches have gone OK, but one didn't.