US-based Stanford University graduates have created an estimated 5.4 million jobs since the 1930s and generate annual revenues of $2.7 trillion.
The 2011 Alumni Innovation Survey found there were 39,900 active companies, such as Google and Hewlett-Packard, that could be traced back to Stanford, which would make it the 10th largest economy in the world.
About 18,000 firms created by alumni are headquartered in California around the university that have aggregate sales of about $1.3 trillion and employing more than three million people.
The survey of the 27,783 alumni and 1,134 faculty since the 1930s who responded also found 29% of alumni and 25% of faculty had founded a for-profit or non-profit organisation.
The Stanford survey, sponsored by the venture capital firm Sequoia Capital (which has backed Google, Cisco, Nvidia, NetApp and Yahoo worth more than $10bn) and backed by the non-profit Kauffman Foundation, showed its alumni had created about 30,000 non-profit organisations.
The Kauffman Foundation had also backed research published in 2009 by Massachussetts Institute of Technology (MIT) that found if the active companies founded by MIT graduates formed an independent nation, their revenues would make that nation at least the 17th-largest economy in the world.
The report, Entrepreneurial Impact: The Role of MIT, globally, a less conservative estimate of their annual world sales would equal $2 trillion, producing the equivalent of the 11th-largest economy in the world.