For the past four years, Prospect magazine has organised an annual award for the best British think tank. Every year we have complained about the lack of bold new ideas. Political think tanks of left, right and centre grow in number and visibility but neither the government nor the Conservatives seem obviously to benefit. What, for example, have our think tanks contributed to the great international debate about US power and democratising the Middle East; or, on the domestic front, what have they had to say about the emergence of "security and identity" issues? The answer in both cases is: very little.

But in considering this year's awards, announced yesterday, our judges concluded that the Prospect complaint was based on a false premise - or rather on two unfair comparisons and a false assumption. The first comparison is with the US think tanks, which are far larger and better-funded than their British equivalents and act as a vital training ground for the more politicised upper levels of the US government. The American Enterprise Institute, such an important focus for the rise of neo-conservative ideas, is not large by US standards but is still more than twice the size of Britain's biggest think tank, the Institute for Public Policy Research.