00297nas a2200121Ia 4500008004100000040001000041041000700051044000700058082001200065245003500077260004400112300001900156160115c99999999ec ||||||||||||   ||spa||  aCCENA  aEs  aUS  aHE10544  aQuarterly journal of economics  aNew YorkbHarvard Universitycnov. 1985  aVol. C Nº (4)