Across the Persian Gulf, rentier arrangements have reinforced pre-existing political establishments. Based on the state's access to rent revenues and its ability to filter them down to the population, three broad types of rentier states can be found in the Persian Gulf: high rentier states (Qatar, the UAE, and Kuwait), mid rentier states (Oman, Bahrain, and Saudi Arabia), and poor rentier states (Iran and Iraq). This typology is supported by data on the state's per capita expenditures on its citizen (national) population. As the empirical evidence demonstrates, rentierism needs to be politically contextualized. In much of the current literature on rentierism, focus has been on arrangements in the political economy of governance, and the consequences of those arrangements between specific economic actors and the state. This does not take into account variations in the rentier states' institutional make-up and functions (the multiple and different ways in which rent revenues have been distributed to--or trickled down to--the population), society-specific dynamics such as sectarian divisions and tensions (as in Bahrain and Saudi Arabia), or national peculiarities such as confederate arrangements (as in the UAE). This paper offers a typology of states in the Persian Gulf by dividing them into the three categories of high, mid, and poor rentier states. Based on this typology, Persian Gulf states in each of the categories are likely to experience, respectively, absence of socially-generated pressures for political change, occasional pressures for political (marginal) reform, or frequent bouts of political instability.