THIS study attempts to evaluate the importance of some influences on inter-industry changes in average hourly earnings for the period I939 to I947 in manufacturing. We consider the relationships between earnings changes and the original earnings level, changes in production, employment, productivity, the importance of wages in total costs, and the extent of unionization. Our statistical investigation covers 57 manufacturing industries, including all those industries for which Census Bureau output indexes, or combinations of them, comparable to B. L. S. data on hours and earnings were available.'