Google has an engineering office here in Pittsburgh right down the road from CMU. So do a lot of other tech companies. A huge part of that is the sheer number of colleges in the area, low cost of living, and apparently the booming food scene with lots of creative chefs due to low rents [0]. Not sure if I'm wiling to buy that last one as a tangible factor in economic growth, but it certainly tastes good in the interim.

0. http://www.nytimes.com/2016/03/16/dining/pittsburgh-restaura...