It's been studied quite a few times and links have been identified. Here is one from 2004. https://scholar.google.co.uk/scholar_url?url=http://web.hks.harvard.

It's been studied quite a few times and links have been identified. Here is one from 2004. https://scholar.google.co.uk/scholar_url?url=http://web.hks.harvard.edu/publications/getFile.aspx%3FId%3D106&hl=en&sa=X&ei=QtLrYv6nE4eKmgGRsI-gBw&scisig=AAGBfm2vnLyIwuzPIueISqVsf4k1hYaUHA&oi=scholarr https://scholar.google.co.uk/scholar_url?url=http://web.hks....