It's where I cut my chops because I could get a 6 figure engineering job without a relevant degree. Very few people expect to stay in a city permanently, and remember many of those workers aren't even citizens, so many of them plan to return "home" at some point.
This doesn't mean anything unless the influx is less than the outflux.
That said, I'm part of the 83% who are planning on leaving, but there are two main problems:
• If I leave, where will I go? As many faults as SF has, it's still a beautiful, world class city, rich with culture. Walkability is huge for me, and I don't want to live someplace where I'm tied to my car.
• Salary. Usually the cost of living follows the pay scale of a local economy, but that doesn't help you when you want to buy things priced at a national level: computers, cars, bikes, etc. If you earn $160k/yr, buy a new MacBook Pro isn't a big deal; if you make $60k/yr, you have to put a little more thought into it.
I see this brought up a lot, but these expenses are such a small portion of my outlay that it barely moves the needle. Maybe I'm just weird.
Also, cars do vary across geographical areas. The MSRP may be the same nationally, but the drive-off price is pretty variable.
If you're really affording all these things then your housing expense is manageable.
But most in these cities are not. At least in NYC it seems to be just trust fund kids who aren't running off debt / paycheck to paycheck living.
You'd need to put down $50k to mortgage a 3-bedroom house in a good school district normal housing market, or $250k to mortgage a 2-bedroom condo in a distressed urban neighborhood. That $200k gulf is 10 years of maxed-out 401k plus a new top-of-the-line Mac every year. Hardly anyone has that much to cut. But if they did, after 10 years, the gulf in necessary down-payment would be much wider than $200k and they'd still come up short.
That's why people are comfortable entering these situations as new grads (you can have a comfortable life as a young single renter in a small or shared space), but feel a need to leave them eventually (starting a family is basically off the table as long as you live there, and you're always at risk of being priced out if your rent rises faster than your salary).
Lyman Stone wrote a good piece on this where he speculates that part of the reason Millenials have been clustering in cities is that "Given that student loans have a fixed nominal value, they are often easier to pay off in high-wage, high-cost cities."[1]
[1] https://medium.com/migration-issues/millennials-have-less-de...