Look at where major tech cos. (by stock market value) are HQ'd
Many "fabled" regions (and engineering schools) from ~20yrs ago like Bos' Route 128, etc are amusingly irrelevant today
Chic has no relevant tech cos.; Moto is a dying midget up in Schaumburg; biggest cos. in Chic are McD's and Abbott
Bos only has puny EMC (despite MIT in region

)
Seattle only has stagnant MSFT and small AMZN (and no notable engineering school)
Aus has dying Dell (and no notable engineering school)
LA has puny Broadcom (Caltech is a nonentity in alums who've achieved much in tech)
SiliconValley has a litany of $100Bn+ mkt cap tech giants...Oracle, Google, Apple, Cisco, Intel, HP...and is most likely to produce future googles as most of world's leading VCs are based in SV and Stanford and Berkeley are both based in region (and nearly every top grad of U-IL Engineering or MIT heads to SV to go to grad school or to get a job or to start a new co.)