The analysis of labour disputes in Korea and Japan indicates that to the extent that national labour relations move towards the institutionalization of collective bargaining, the determinant of strike activity shifts from a political to an economic process. Labour disputes in countries with under-institutionalized industrial relations, e.g., Korea and pre-1955 Japan, coincided with social and political crises. In this setting, relative deprivation among workers plays the role of an intervening variable in determining the severity of the collective action if political factors provide an opportunity for the mobilization of workers' discontent. The Korean case clearly shows that strike activity varies both up and down with changes in the level of relative deprivation. Under a well institutionalized industrial relations setting, for example Japan after 1955, levels of unemployment and changes in consumer prices are important predictors of strike activity.