Well, Duuhhhhh!
In other news Harvard researchers have also discovered that sex is the leading cause of pregnancy.
This is not obvious as you are making it out to be, in fact, it is plain counter intuitive, and calls into question many deeply accepted ideas about the multiplier effect of transactions in a local economy.
And, this study reached back 40 years so an argument that economies are less local now than ever doesn't explain this either.
Frankly, using traditional economics, it is downright hard to explain this result and the professors who wrote it were reduced to fumbling to come up with a plausible reason.
The best explanation put forward is that Government spending very rarely supports or encourages the innovation that builds new businesses. Instead it goes to connected political insiders that represent larger firms and potentially firms that provide jobs in the district but little more because of the basic insecurity of government programs where the spending is normally limited in time and then dries up.