Consider our difficulties avoiding junk food and overspending. Such addictions were carefully planned-for by professional marketing teams.

Economics is (now) about emotion and psychology.

Can a controlled experiment explain why people like Kewpie dolls in one year, Beanie Babies in another, and American Girl dolls this year? Yet social scientists are asked to answer analogous questions. We economists and perhaps psychologists shouldn't overreact to the derision. That is, we shouldn't try to overlay a false sense of precision on our admittedly squooshy work.

Marketers know that if people you respect - perhaps laughably including entertainers and athletes - say they like a product, you're more likely to buy.

A major boom in real stock prices in the US after Black Tuesday brought them halfway back to 1929 levels by 1930. This was followed by a second crash, another boom from 1932 to 1937, and a third crash. Speculative bubbles do not end like a short story, novel, or play. There is no final denouement that brings all the strands of a narrative into an impressive final conclusion. In the real world, we never know when the story is over.

In the short run and for decisions unlikely to have broad impact, it may be more cost effective to use just one expert.

Each profession has its own toolkit.