  Spanish astronomy has grown rapidly during the 1990s. The number of papers
published per year has doubled, to about 4% of the world total. The number of
high-impact papers, however, remains constant at about 1% of the world total.
Papers from France, Germany and Italy also have lower impact than their numbers
suggest, while for the US, UK, Japan, Netherlands and Australia, the fraction
of high-impact papers is approximately the same as the fraction of all papers.
We suggest a few possible explanations for this difference.
