@techreport{NBERw13760,
 title = "Renewable Energy Policies And Technological Innovation: Evidence Based On Patent Counts",
 author = "Nick Johnstone and Ivan Hascic and David Popp",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "13760",
 year = "2008",
 month = "January",
 URL = "http://www.nber.org/papers/w13760",
 abstract = {This paper examines the effect of environmental policies on technological innovation in the specific case of renewable energy. The analysis is conducted using patent data on a panel of 25 countries over the period 1978-2003. It is found that public policy plays a significant role in determining patent applications. Different types of policy instruments are effective for different renewable energy sources.},
}