It seems odd to claim this increase is due to keeping up with others' weddings when inflation between 1990 and 2015 was roughly the difference here. The weddings were/are more expensive because everything was/is more expensive. $15,000 in 1990 had the same purchasing power as ~$27,000 in 2015. So this hardly seems related to bigger, more extravagant weddings. People have had to spend more to maintain the same quality of wedding as the previous generation.