One of the best passages in Geoffrey Miller’s Spent shows economists at our worst:

My crisis point came at a 1999 conference that I organized in London on the origin of people’s economic preferences.  We psychologists thought that economists would enjoy hearing about our preference experiments, so that they could develop more accurate and sophisticated models of human economic behavior.  How wrong we were.  It became clear that economists still followed a “revealed preferences” doctrine, which holds that consumer preferences are psychological abstractions – hidden, hypothetical states that cannot be measured or explained apart from the purchases that they cause.  If preferences are revealed only through purchases, and not through questionnaires, interviews, or focus groups, then it is redundant to study preferences apart from actual consumer spending patterns, to speculate about the origin of preferences, or to conduct market research on preferences for hypothetical products… So the economists gradually drifted away from the conference, leaving the psychologists to nurse our bruised egos, in the company of some strange-looking folks we hadn’t seen before.

These folks weren’t like the academics at the conference… They were the marketers, and they were hot for psychology.  They actually cared about people’s preferences – where they come from, how they worked, and how to profit from them.  I talked for hours with them, and a new world opened up.

This anecdote rings true.  Many – perhaps most – economists would scoff at Miller’s search for the origin of preferences.  Why?  Because it’s not economics.  And why isn’t it economics?  Because we don’t do it.

To any psychologists who have encountered this mentality, all I can say is: We’re not all like that.  I found Miller’s questions immediately fascinating.  I furrowed my brow when I realized that economists usually leave these important questions to a field I know only by name – “marketing.”  There’s no excuse for it.

After I read this passage, I was eagerly expecting Miller to give economists a primer in marketing.  But the chapter on “what economists should learn from marketing” never comes.  Instead, Miller quickly starts giving marketers a primer in intelligence and personality research!  It’s a confusing rhetorical strategy:

Step 1: Tell economists they need to learn about marketing. 

Step 2: Tell us very little about mainstream marketing research. 

Step 3: Tell marketing people that they need to learn more psychology.

Frankly, Miller barely seems more interested in actually listening to marketers than the typical economist.  Still, this would be easy to forgive if Spent showed that intelligence and personality research made mainstream marketing research obsolete.  As I’ll soon argue, though, Miller dismisses mainstream marketing far too quickly.  Intelligence and personality research may be able to supplement standard approaches, but they can’t credibly replace them.