A Behaviouristic Approach for Measuring Poverty : The Decomposition Approach - Empirical Illustrations for Germany 1995-2009

In this paper an alternative approach with regard to poverty measurement is discussed: the so-called decomposition approach. This method differentiates between various social groups in the sense that for each group a separate poverty line is determined. E. g., household size might be a criterion for such a social differentiation. By doing this, the problem of traditional poverty measurement to refer to income-independent equivalence scales is principally avoided. Moreover, the further problem of the traditional method, namely to determine a (general) poverty line as a more or less arbitrary fraction of society's mean welfare level, does not exist, on principle, in the decomposition approach. Present author's own calculations reveal higher poverty levels indicated by this approach compared with the conventional method of measuring (income) poverty. Since it appears to be realistic that some people perform their poverty assessments through a “mixture” of their own group's and overall welfare levels, at a plausible degree of economies of scale (i. e., Buhmann et al.'s θ > 0.65) the poverty levels of the decomposition approach can be interpreted as upper limits for the “true” level of poverty, and, conversely, the degree of poverty ascertained by the conventional approach can be seen as a lower limit for “true” poverty