Daniel Kahneman, a psychologist whose work casting doubt on the rationality of decision-making helped spawn the field of behavioral economics and won him a Nobel Prize, has died. He was 90. He died on Wednesday, the Washington Post reported, citing his stepdaughter, Deborah Treisman, the fiction editor for the New Yorker. No other details were available. Kahneman upended assumptions about rationality that had dominated economics for decades. He was able to show the logic behind a number of puzzling behaviors — why people refuse to sell stocks that have lost value, or why they will drive to a distant store to save ... (full story)