IDEAS/RePEc has (at last) released rankings of universities. Previous rankings spread economists over department, institutes and what not, so that the institutional ranking reflected fractionalisation as much as quality.
The new rankings are here: http://ideas.repec.org/top/top.toplevel.html
No big surprises. One non-US university (U London) in the top 10, two (Oxford U) in the top 20. Tilburg U (at 27) is top of the non-Anglon-Saxons, beating Toulouse (at 32).
UCD is top of the Irish at 98. TCD comes at 143. Ireland does better than Norway and New Zealand but worse than Denmark, countries with a comparable population.
Not bad. Could be better.