1. Even though they represent a large share of the sample, Japanese hosts do not drive the results significantly. To check robustness, the analysis was run without the Japanese hosts and the results differed only slightly from the whole sample. Whenever specific results obtained without Japanese hosts were found to differ substantially from the whole sample, the difference is noted in a footnote.
2. Funding data are converted using the OECD’s official statistics on purchasing power parities (PPP) for each country for the year 2001. See,.