A trio of economists looked into the question and have published their results (via the Freakonomics blog). Charted above are the percentages of forgone work time dedicated to various activities outside the labor market. In other words, this is what the underemployed or out of work are doing with the time they would otherwise spend at work if they could find a job or become fully employed. The researchers found that while the un- and underemployed are spending a lot of their extra time being productive around the house, about half of it is going to leisure activities. (Percentages in figure above do not add to 100 percent due to rounding.)
The largest slice of time goes to sleep. Overall, approximately 50 percent of the forgone labor hours goes to leisure, which includes sleeping, watching TV, and socializing with friends. Another 30 percent goes to "non-market work"--things like cleaning, cooking, and doing household repair work. The rest is divided among various other activities that include child care, education, and religious services. And a final 1 percent goes to trying to find a new job--which might strike some as low. Though, if they are as few jobs out there as some say there are, maybe it's not.