1. R. May Science 275 793 (1997).
2. May's Policy Forum was derived in part from a benchmarking study [ The Quality of the UK Science Base (Office of Science and Technology U.K. Department of Trade and Industry London 1997)] which in turn draws heavily on an analysis of Australian research [ Australian Science: Performance from Published Papers (Australian Government Publishing Service Canberra 1996)].
3. The G7 countries are Canada Germany France Italy Japan the United Kingdom and the United States.
4. In (1) the citation period is given as 1981–84 [table 1 in (1)] but in the U.K. report and in the Australian study [(2) tables 5 and 2.1 respectively) it is given as 1981–94. We have assumed that the dates in May's Policy Forum are a typographic error.
5. One way of estimating which funding year is relevant is to analyze the age distribution of articles cited in a leading general science journal. For the 1994 editions of the journal Nature the median age of papers cited is 3 to 4 years. If the age distribution of papers cited in 1994 is similar to the age distribution of papers cited in all previous years back to 1981 then the median year of publication for papers cited in Nature between 1981–94 is 1985/6. The research reported in the cited papers would plausibly have been funded several years previously. Therefore if Nature is representative of science in general (spanning many disciplines) it is most reasonable to compare funding in the early to mid 1980's with citations achieved during 1981–94.