The objective of this paper is to explain differences in the economic performance of selected advanced capitalist countries between 1960 and 1980, such as rates of unemployment, level of inflation rates and economic growth rates, with the presence or absence of corporatist arrangements between major interest groups and the State, and with the strength of leftist parties in these nations.

In reviewing the literature, I have found basically two approaches to corporatism: ( 1) a 'structural' approach, which emphasizes sociological characteristics of the actors, especially labor unions; and (2) a 'functional' approach, which stresses elements of policy formation and implementation. Using factor analysis, I will create a corporatism score for each country.

According to Olson's 'Logic of Collective Action', nations with corporatist arrangements (large and centrally organized interest groups) should do better economically (in terms of growth rates) than nations without these arrangements. However, this application has been criticized, since economic growth would be a relatively automatic function of size and degree of organization of interest groups in a given nation, and would not leave any room for strategic considerations, which can be influenced by political parties.

Therefore, I will perform a LISREL analysis for two competing models: (1) an 'additive' model, where I compare the independent effects of corporatist arrangements and leftist parties on strike activity, unemployment rates, inflation rates, and GDP growth rates; and (2) a 'multiplicative' or conditional model, where the effects of corporatism on economic performance depend on the strength of left parties, and vice versa.

My findings do not strongly support the 'additive' model, whose policy implications for countries that wish to be more successful economically in terms of growth of GDP would be to pursue more corporatist strategies. With the notable exception of economic growth rates, on which the combined effects of corporatism and left parties have a strong, negative effect, the 'multiplicative' model is far more successful in explaining differences in economic performance among nations: I have found strong negative. indirect effects of this combined index on unemployment and inflation rates. An implication is that those countries with strong left parties and already existing corporatist arrangements could pursue strategies to extend corporatist arrangements with the hope of gain, while countries without strong left parties and corporatist arrangements might abstain from a policy of becoming more corporatist, since absence of strong labor-based parties might impede rather than promote economic growth. They might even try to reduce their extent of corporatism.