Redfin CEO Glenn Kelmann recently crunched the numbers on the rise in home prices as tech hiring picks up:

Three weeks ago, Redfin published a report showing that one in four Silicon Valley home-buyers is looking to buy a home outside of Silicon Valley, up from one in seven in 2011. This digital diaspora promises to bring some of Silicon Valley’s wealth-creation to cities across the country, especially Seattle, Portland, Austin, Boston and Denver. It has already begun to increase the cost of living.

But exactly how many technology workers does it take to increase home prices in these cities? To answer that question, Redfin took the hiring of the four largest Internet-related companies — Google, Apple, Facebook and Amazon, in Silicon Valley and beyond — as a proxy for each metropolitan area’s overall growth in technology hiring. What we found is that for every 1% increase in technology workers, there’s a roughly half-percent increase in home prices above and beyond the national rate of appreciation.