On Thursday, the Center for American Progress, a prominent left-leaning think tank that often cultivates policy ideas later adopted by the Democratic Party, proposed a two-year freeze on the prices of 22 food items, such as strawberries and steak. “Price caps interfere with the very basics of a capitalist economy,” said Steven Kaimin, an economist at the American Enterprise Institute who read the Center for American Progress paper before its publication. “Maybe it’s impossible to produce eggs at $3. Maybe the cost of producing them is $3.50. In which case the eggs come off the market entirely, or … only...