Pareto improvements: a cautionary tale

I heard this week of a friend who was writing a paper on supermarket pricing.  Some of the research that the shop had carried out (which, unfortunately, remains confidential) showed that people were, at times, put off buying items if they were in a buy-one-get-one-free deal.  Indeed, there were a few items that actually sold worse when they were in a deal than when they were out of it, particularly when you looked at individual shopping habits – yes, those Clubcards are pretty useful from a econometrics point of view. Continue reading “Pareto improvements: a cautionary tale”