$40k isn't much anywhere in the US, not just in San Fransisco. Mississippi is the poorest state in the US, with a median household income at $37,095.

Cite: http://www.parade.com/166996/viannguyen/what-are-the-10-rich...

I wonder where X% or $Y over or under median has a bigger impact on quality of life.

What do you think has the bigger impact on quality of life, services or goods?

X% over in a wealthy city is going to give you the most extra money, good for buying BMW's, travel, and things on the internet.

$Y over in a poor city will make you locally wealthy, so you can eat at the nicest restaurants, afford the nicest houses, and maybe have hired help.

A good point.

I've crashed at places like the StartupHouse in SF for very low rents. They had closet sized private rooms or bunk bed rooms for even cheaper. A private room in a shared apartment down in East Palo Alto was probably the best valley place I stayed, for $600/month. It was easy to Caltrain anywhere needed, including SF. Young people are far more likely to accept college dorm like crowded living conditions like this, though.

I don't suppose I could talk my fortysomething wife into those living conditions, no.

Nor in NY but it happens. A breakdown in location X salaries would be interesting to see. Is this just in the U.S?

In Albany, NY a couple of my friends are making 40,000 as web developers up here.