The academic use of the term 'Rentier states' and Rentier States Theories (RST) became well known after the works of Hazem El Beblawi and Giacomo Luciani on the development of oil rich countries in the Persian Gulf and Arabian Peninsula. They show that rentier states receive income without an increase in the productivity of the domestic economy or political development of the state, that is the ability to tax citizens. The unequal distribution of external income in rentier states has thus a negative effect on political liberalism and economic development. With virtually no taxes citizens are less demanding and politically engaged and the income from rents negates the need for economic development.