The Cost of Being a Female Consumer in NYC [pdf]

Some methodological weaknesses:

- "The prices recorded for the study data were always the full price, regardless of any sale or discount the retailer offered."

- " In some cases, men's products were clearly marked as intended for men, while products included in this study as women's products could be considered "unisex," because the label did not specifically indicate a gender."

- Only looked at retail products, not online.

So there isn't actually much reason to believe that women pay more than men for products, let alone significantly more, but it's still interesting to see the differences in marketing.