1188 PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 2§ have taken policy measures that would have prevented these expen- ditures. MALINVAUD Professor JoHNSON has shown us that long-term forecasts in agriculture were often very poor. I should submit that this is not surprising. The future is difficult to predict anyway; and quanti- tative economics is not an old science. Economist, who only re- cently started to work with real data, have still much to learn in order to predict better. Even considering the present achievements, I would not accept the conclusion that we should no longer try to make long-term projections, Whoever has to decide for the future, must have some idea of the future. Thus, the real alternative is between individual long-term projections and what I would call centralized long-term projections. Professor JoHNSON has not convinced me that we should only rely on individual projections, One of his claims is that individual errors are offsetting. But, in the first place, I doubt whether they really are. Great mistakes have been made during the past 15 years in various industries. My ‘feeling is that, in most cases, the centralized projections were less wrong than the average individual projection. The centralized pro- jection had to fight against the common belief that was generally much too extreme. Such was the case for fuel during the European coal shortage, and again shortly after at the time of the Suez crisis. According to me, econometric studies are usually bringing into the discussion about the future some rational elements which are not taken into account by individuals who have no time to go into a serious analysis. In the second place, even if the errors were offsetting, we should not necessarily be satisfied with the situation. Offsetting errors do not imply good decisions. Each individual decides on the basis of his own mistakes. Decisions will then be inconsistent with one 16] Johnson - pag. 48