First, some statistical analyses.

From Iain Campbell, "Extended working hours in Australia", Labour & Industry; 8/1/2002. "A distinctive problem of extended (or `long' or `excessive') working hours has recently emerged in Australia. The problem is most clearly seen if we focus just on full-time employees -- the core group within the workforce. Previous research (Campbell, 2001) confirms that average working hours of full-time employees in Australia are long, and since the early 1980s they have been steadily getting longer. This is a peculiar trend, at odds with both the long-term historical experience in Australia and the contemporaneous experiences in most of the other advanced capitalist societies grouped within the Organisation for Economic Cooperation and Development (OECD). […]

"An increase in the proportion of full-time workers who work extended hours, predominantly in the form Of unpaid overtime, can be detected in several other OECD countries (OECD, 1998, 157-160; Boulin and Plasman, 1997). However, the increases are generally slight and confined to a small proportion of workers, primarily high-level managerial workers. They do not surface in the averages, because they are generally counter-balanced by a continued decline in working hours for the majority of full-time employees. In Australia, by contrast, the trend towards longer hours is the dominant one for full-time employees. It is widespread and strong, spreading well beyond the ranks of managers and based on patterns of not just extended but often very extended and extremely extended hours."

He goes on to say that a significant proportion of this extension is in the form of unpaid overtime.  Also, that the average full-time working week increased by 3.7 hours between 1982 and 2000, a larger increase than other OECD countries. Between 1985 and 2002, the proportion of employees working 40-45 hours rose from 23.4 to 31.3 percent, while for 45-50 hours it increased from 17.8 to 26.1. The percentage working 50 hours or more rose from 10.2 to 17.4.

Second, a question: If waged work always-already consists of a portion of worktime that is unpaid, then how is it possible to measure 'unpaid overtime'?  Wouldn't it be better to call this an informalised form of wage cutting? 

Some other links here: Work to Live - Shorter Work Time - Four Hour Day - SlowDown