Money/Income has a lot to do with it. Women have climbed up income brackets along with Gays/Lesbians. Men due to laws of the State have been getting raped in income scales and I think NYC has so many more women simply because many men have been squeezed out of the City and moved away. Art and culture have to do with the draw for females but if this were the case the most female obsessed industry ..Hollywood.. would mean that LA should have the same ratios or close to as NYC. In the priciest places you will be finding close too or more females and it has more to do of how Men have falling down the earnings ladder more than anything else.
Men moved out west to the Sun belt and California to find work. Defense and Tech jobs are still largely male dominated and these are bountiful out west. Since women are less willing to re-locate or move (usually) many stuck around, especially in the mid-west cities. If they did leave it was most likely eastwards to chase Gubmint money in DC, Schooling in Boston, or a TV lifestyle in NYC.
Men moved out west to the Sun belt and California to find work. Defense and Tech jobs are still largely male dominated and these are bountiful out west. Since women are less willing to re-locate or move (usually) many stuck around, especially in the mid-west cities. If they did leave it was most likely eastwards to chase Gubmint money in DC, Schooling in Boston, or a TV lifestyle in NYC.