A variety of limitations exist in this study. One of the most crucial limitation lies in the definition of the IV-D population. Since there is no direct question on the April CSS survey regarding receipt of IV-D services, this number had to be estimated through the use of variables from both the March and April surveys. Changing some of the assumptions used in constructing the IV-D population could significantly affect its size and its interaction with the various characteristics. For example, former TANF families who do not report contact with the IV-D program could be erroneously identified as being outside the IV-D service population even if, based on their former welfare status, they are still receiving services. The use of "family" variables from the CPS, which include only the family and related subfamilies, may also affect the data.
Unlike the previous reports on the circumstances of this population, this report uses data from a period several years after the implementation of the TANF program. In fact, while comparisons over time have to be made with care due to revisions made by the Census Bureau to the CPS/CSS data file over the time period covered by these surveys, there has been a reduction in the percentage of child support-eligible families receiving TANF cash assistance. Since, according to the assumptions of this analysis, receipt of cash assistance is one of the variables that places families in the "receiving IV-D category", this reduction has led to a subsequent decline in the percentage of families receiving IV-D services between 1995 and 2001.