4 Data
The empirical analysis is based on the sample survey of household income
and expenditure, abbreviated by its German initials EVS (Einkommens- und
Verbrauchsstichprobe).42 The EVS is part of the German system of house-
hold budget surveys, which consists additional to the EVS of the annually
conducted current household budget survey (Laufenden Wirtschaftsrechnun-
gen, LWR). The EVS is a cross-section household survey, conducted every
five years that started in 1962/63 in West Germany and was extended since
1993 to East Germany. As statistical unit a household is defined as a group
of persons whose command over income is shared, independent of their kin
relationship. By a net sample (fully completed questionnaires) of 55,110 vol-
untarily participating households in 2008, the EVS is the largest survey of its
kind in the European Union. The EVS is a quota and not a random sample
so that statistical errors cannot be calculated in the theoretically exact way.
The annual current population survey of Germany, the Microcensus, serves
as a benchmark for recruiting the participants, who earn a small honorarium.
Some of the quotas cannot be achieved completely, so that a final weighting
has to be conducted. To publish results on the federal state level, the EVS
sample is weighted according to the criteria “type of household”, “social po-
sition of the household’s reference person” and “income bracket” for each
federal state using the current Microcensus results.
The EVS consists of four parts:
1. Initial household interview, in which the socio-demographic informa-
tion about every household member, the overall housing situation and
the endowment with durable consumer goods are enquired.
2. An appendix to the initial household interview evaluating the financial
assets and debts of the household.
3. A household book, containing all kinds of income - including public
and in-kind transfers - and expenditures on all categories of private
consumption, has to be kept for three month.
4. A sub-sample of 20% of the participating households has to keep for one
month another household book (detailed log book) in which all expen-
42For a comprehensive description of the EVS see [26]Statistisches Bundesamt (2005).
27