Solidificación Direccional en Metales Fundidos Saturados de Gas

This part of the report provides a description of the participation of eligible groups in LPWFI or NDLP. The eligible population of new/repeat and existing claimants on IS from administrative data during the year 2001/2002 was first identified. Then, these eligible groups were observed until April 2004 in a dataset merging benefit and participation in LPWFI and NDLP from the New Deal Evaluation Database (NDED). Based on these merged data, a description of the participation of eligible groups shows very heterogeneous (differing) sequences of multiple and repeated treatments. The description of multiple and varied treatments is crucial for this impact analysis. This is because the standard methodological literature assumes that a treatment is offered only once. For the programmes considered here, this assumption does not hold. The introduction of review meetings for LPWFI after one year explicitly aims at the repeated participation in LPWFI by the eligible groups.

As there were a substantial number of repeated treatments, the various treatments that can be observed in the merged data need to be described in order to decide which treatments can be evaluated. The description of the multiple treatments consisting of either LPWFI or NDLP is essential for a well-designed categorisation of the treatments that will be evaluated. Additionally, it was important to consider the following:

• if the repeated treatments occur over a short time period, it might be justified to aggregate first and second treatments as a combined intervention and to estimate an aggregate effect of these sequences;

• if the treatment is offered relatively late after the start of the eligibility, only a remaining fraction of the originally eligible persons might participate, resulting in composition effects that should be taken into consideration when evaluating. The description of multiple treatments allows the application of the matching estimator to identify the effects of NDLP in the LPWFI period, the LPWFI effect on NDLP participants and the joint effect of both interventions. These estimates however have to consider how the actual participation differs from the initially planned delivery of the programmes. In addition it is necessary to adjust the time periods for which the effects are evaluated.

2.1.1 Institutional regulation and delivery of LPWFI

This subsection provides a brief review of the eligibility criteria important for this analysis. After that, the basic eligible groups were identified using the benefit data. As previously mentioned, lone parents receiving IS payments variously become eligible for LPWFI according to the start date of the claim and age of youngest child (see Table 2.1):

• new/repeat clients initially eligible for LPWFI consisted of lone parents whose IS claims were initiated after the commencement of the LPWFI system on 30 April 2001 if their youngest child was aged at least five years and three months and at most 15 years nine months at the start of the claim;

• the eligible group of existing claimants consisted of lone parents on IS before or on 30 April 2001, with youngest child aged between 13 years and 15 years 9 months to this date. The eligibility for LPWFI was extended successively to other groups.

In addition to the extension of LPWFI coverage from April 2002, review meetings were started as a follow-up for IS claimants remaining on benefit. The introduction of review meetings was staggered. Further background regarding the LPWFI and NDLP programmes is presented in Section 1.1.

The separate analysis for existing claimants and new/repeat claimants has advantages for this evaluation. It will enable separate estimates of additionality for the existing claimants and the new/repeats. This is useful as it is likely the estimates are different, and the estimates for the new/repeats provide a better picture of the longer-term additionality of the programme while the existing claimants are present only in the short- to medium-term.

For the impact analysis, and the descriptive analysis, breakdown by existing claimants and new/repeat claims has other, further consequences. After the introduction of LPWFI, particularly for those among the existing claimants, earlier NDLP participation could precede LPWFI participation and any subsequent NDLP entry. This earlier NDLP participation complicates identification of that group who have not participated in NDLP, and who enter NDLP only after the LPWFI. These differences were considered, and former NDLP participation (any NDLP caseload start before 30 April 2001) was excluded. Consequently, only NDLP participation after 30 April 2001 is evaluated. With this restriction, any NDLP participation in the LPWFI period is considered to be a different treatment than NDLP before April 2001. This is important to the definition of the impact identified with the analysis, as the comparison and participation groups define the impact estimate.

The introduction of the review meetings creates a complex participation structure for the eligible persons remaining on benefit for one year after their initial participation, because this group receives the treatment twice or more often. Both the extent of initial as well as repeated participation, and the timing of first and second participation, are discussed in Section 2.2. This is especially important for the choice of the treatments evaluated. It is also important to the expected way in which a repeated offering might change the estimated treatments effects.

Table 2.1 Eligibility for LPWFI

Financial year 2001/2 2002/3 2003/4 2004/5

New/ New/ New/

Existing repeat Existing repeat Existing repeat Existing

Benefit Existing New/ Existing New/ Existing New/ Existing receipt spell on repeat spell on repeat spell on repeat spell on

IS on claim IS IS on claim IS IS on claim IS IS on 30/4/01 from 30/4/01 from 30/4/01 from 30/4/01

30/4/01 30/4/01 30/4/01 until until 1/4/02 01/4/02 Age of 13-15 >5¼ 9-12 >3 5-8 >0 0-4 youngest child

Review After 12 After 12 After six After six After six After six After six meetings months months months months months months months