Financial work incentives for disability benefit recipients: lessons from a randomised field experiment

Table 3 Sampling structure

	Obs.	% full sample	Stratified
1) Full sample	37,853	100 %	No
2) Invited for survey participation	8,000	21 %	Yes
3) Survey participants	4,049	11 %	Yes
Nonparticipants	3,951	10 %	Yes
4) Experimental sample	6,020	16 %	Yes
Seed capital high	2,000	5 %	Yes
Seed capital low	2,000	5 %	Yes
Control group	2,020	5 %	Yes
5) Simulation sample	2,273	6 %	Yes

Note: Selection for participation took place in two steps: From the total of 37,853 individuals who were observed in the administrative records in June 2009, 2,814 individuals have been excluded, primarily as their current residence was outside of the cantons of St. Gallen and Vaud. From the remaining 35,039 individuals, 8,000 individuals have been randomly selected to participate in a survey. Random sampling was stratified by three age groups. The experimental sample consists of all individuals who were invited to participate in the survey but excluded individuals who are likely to live in a nursing home and individuals with a disabled partner (to avoid spill-over effects if one person gets randomised into the low and the other person gets randomised into the high seed capital group). The simulation sample consists of all individuals in the treatment and comparison group who participated in the survey and have non-missing information on incomes and benefit payments. Individuals who have never worked before DI entry were excluded, because wage predictions are based on work history prior to disability. Source: Own calculations based on administrative and survey data, provided by the Federal Office for Social Insurance, Switzerland