A university study reported that between 1975 and 1983 the length of the average workweek in a certain country increased significantly  A governmental study, on the other hand, shows a significant decline in the length of the average workweek for the same period
Examination of the studies shows, however, that they used different methods of investigation; thus there is no need to look further for an explanation of the difference in the studies' results
recognize that varying economic conditions result in the average workweek changing in length