Another consideration in the design of applicant samples is that states must accurately forecast the influx of applicants eligible for random assignment to achieve sample size goals in the expected time. Overestimating applicant flows puts states at risk of either having an inadequate sample or needing to extend sampling. Factors to be considered in estimating applicant flows are (1) the proportion of applicants who will have already been through random assignment as part of a previous welfare spell, (2) the proportion of applicants who are transfers from another site (and thus, in most demonstrations, ineligible for sampling), and (3) whether the sample frame includes the full sample relevant for random assignment or excludes some relevant cases. In addition, the ability to forecast general caseload trends is always imperfect; for example, the strong national economy has contributed to greatly reduced AFDC caseloads in many states and thus made it harder to meet sample goals in some evaluations. The intervention itself may reduce applications; this is a substantial problem for the analysis (as discussed in Chapter VI), but it also affects sample sizes. Many of the evaluations reviewed did not take these issues into account and therefore have had difficulty meeting applicant sample goals.