paradigm in monetary theory. Besides promoting their paradigm as an alternative foundation for triggering economic development (much in line with the insights of Hernando de Soto, Tom Bethell and Richard Pipes), Steiger has applied it to an analysis of the eurosystem. While this approach has similarities with institutional economics, its major differences are (1) a non-universalist, cross-cultural approach that is in line with results from economic anthropology (Marshall Sahlins, Karl Polanyi, Marcel Mauss and others) and strongly doubts on the "homo oeconomicus" concept. It provides instead a specific explanation of various strategies of economic efficiency become functional only in monetary economies based on property and enforceable contracts;. Heinssohn proposes a reconstruction of the connection between property, enforceable contracts, interest, credit/money and the banking system and a possible explanation for technical progress and innovation. The difference in innovativity and progress between the monetary economics of antiquity and modern times is being explained as well. Heinsohn and Steiger's model has been discussed in some post-Keynesian circles, and it has been criticized by Nikolaus K.A. Läufer. Demography Heinssohn used demographic patterns to explain various historic events and tendencies. His work on genocide and antisemitism was strongly influenced by his demographic studies. Youth bulge and lack of fertility In his theory about the "youth bulge", Heinsohn argued that an excess in especially young adult male population predictably leads to social unrest, war and terrorism, as the "third and fourth sons" that find no prestigious positions in their existing societies rationalize their impetus to compete by religion or political ideology. Heinsohn claims that most historical periods of social unrest lacking external triggers (such as rapid climatic changes or other catastrophic changes of the environment) and most genocides can be readily explained as a result of a built up youth bulge, including European colonialism, 20th century Fascism, and ongoing conflicts such as that in Darfur, The Palestinian uprisings in 1987-1993 and 2000 to present, and terrorism. Historical demography Heinsohn discussed the origin of modern European demographic patterns (starting with an intense increase in population growth in early modern times, leading to sub-replacement fertility at the dawn of the 21st century), including an interpretation of the European witch hunts of early modern times as pro-natalist re-population policy of the then dominant Catholic Church after the population losses the black death had caused. This interpretation has received mixed responses. It has been criticized and rejected by German historians