Oliver Alexy of Technische Universitat Munchen (TUM) Business School
has written an interesting paper titled "Putting a Value on Openness:
The Effect of Product Source Code Releases on the Market Value of
Firms." The research traces the impact of open source on company
market valuations from January 1, 1999, to April 30, 2007. The
research is hampered somewhat by a lack of private-company data, but
it still offers up some useful conclusions.