Five ways
Three on food

Different schools of economics

The homepage for Swarthmore's economics department presents seven "Questions of Economics". The first one is "What activities should governments undertake, and what can be left to markets?"

"Left to markets"??

In the department in which I was trained and the one in which I work, this question would be posed differently: "For what activities is the market sufficiently inefficient--explain carefully why!--that we should consider allocating by government instead?"