Prof. Robert Allen discusses how the desert environment led to a unique economic structure-"from the sand up". Bob takes us through the economic implication of communal lands and describes the differences between the nomadic (Bedouin) and oasis economies. He suggests that religious structures were convenient in eventually consolidating various regions/tribes in the form of states. We also consider the incentives for a unique type of slavery, that arose from the nature of date farming/pearl di...