If you want to break the ice at a corporate seasonal party in America these days, try popping this revealing question: which part of the US has the highest proportion of entrepreneurship?

“Silicon Valley” would be a predictable, and understandable, answer. After all, in recent years, the San Francisco region has been an epicentre of US innovation. Mark Zuckerberg, the founder of Facebook, seems to epitomise the entrepreneurial dream; particularly since his recent announcement that he plans to donate most of his largesse to social causes.

But here is a curious little detail of America’s economy today: if you want to understand the real nature of entrepreneurial activity, do not look to Silicon Valley or Mr Zuckerberg. The biggest hotbed of urban entrepreneurship, as measured by the number of small companies per head, is now New York, not the West Coast, according to research by the Kauffman Foundation, a think-tank. Boston sits in second place in terms of “entrepreneurship”, followed by Providence, Rhode Island. Meanwhile, San Francisco is fourth, just ahead of Miami in Florida and Portland in Oregon. Main Street is giving the Valley more than a run for its money.