The authors clearly state they used statistics to adjust for all the basic factors like what they buy (using single people instead of married couples) etc. so a

The authors clearly state they used statistics to adjust for all the basic factors like what they buy (using single people instead of married couples) etc. so after you read the 3 pages there are not a lot of options left. I do have an idea that they didn’t test however: The women I have dated in the past seem to have selective memory about what they purchase. They seem to shop and talk about shopping like people who gamble. They will tell their friends all about the item they saved $50 on 8 months ago but rarely talk about the items they overpaid for. (gamblers like to talk about wins, but not losses) I can't speak to the shopping habits of most men, but I go to a store and quickly get what I need for a reasonable, but sometimes high price and exit as quickly as possible. I rarely remember what I paid for particular items I got on sale, but know that a shirt should cost about $50. Etc. Is it possible that the sample of the women I have dated are similar to a statistically significant number of women who have selective memory about past purchases? I obviously don’t know the answer, but if it is true, I think that is a reasonable thing to test and is backed by the fact that women perceived clothing as a significant driver of the inflation above the men (page 3). [Note] Some of what may be driving this is cultural like women not wanting the guys they are with to think they are wasting money and the desire to talk about the deal they got like shopping is a skill with their friends. This may be US/Swedish style cultures. Researchers could test this by surveying other cultures which are less similar to US culture which couldn't prove this theory, but could disprove it.