Richard H. Thaler, the “father of behavioral economics,” has this week won the 2017 Nobel Prize in Economics for his work in that field. Thaler has long been known for challenging a foundational concept in mainstream economics — namely, that people by-and-large behave rationally when making purchasing and financial decisions. Thaler’s research upended the conventional wisdom and showed that human decisions are sometimes less rational than assumed, and that psychology in general — and concepts such as impulsiveness — influence many consumer choices in often-predictable ways. Once considered an outlier, behavioral economics today has become part of generally accepted economic thinking, in large part thanks to Thaler’s ideas. His research also has immediate practical implications.…