Abstract: This article offers a conceptual framework for analysing involuntary unemployment using the concepts of justice and income distribution within a market economy. Conventionally, it is argued that involuntary unemployment causes a deadweight loss in social welfare, because it involves the under-use of a productive resource. We explore this efficiency argument with a public choice approach, employing the notion of homo oeconomicus. We contrast this with a perspective using the concept of homo politicus, which stresses social justice. We apply our findings to the special case of German social reform, especially Hartz IV, and show that some of its policy recommendations are in accordance with our analysis.