Some limits on the comprehensiveness of the benefit-cost analysis should be recognized. Some program effects, whose costs and benefits are difficult to quantify or to express in dollars, are not estimated. For example, this analysis does not include estimates of out-of-pocket expenditures (for child care, transportation, clothing, and so on) that sample members incurred when they went to work.(13) In addition, the estimates in this chapter reflect the direct effects of programs and do not consider secondary effects. These secondary effects include the possible displacement of other workers by the increased employment of program group members; these displaced workers may have become unemployed or employed in lower-paying jobs. In addition, the analysis does not consider the sample members' forgone personal and family activities that resulted from increased work or the intrinsic benefits of education that are not reflected in earnings. The analysis does not place a dollar value on family or child well-being or the clear but difficult-to-monetize benefits associated with society's (or sample members') preference for work over welfare.