Add and rule
提出一种新机制解释资源丰富国家的政治经济不平等：独裁国家对待移民不如民主国家慷慨，导致民主化后遗留过多移民，使民主吸引力下降，从而让独裁者更容易维持统治并攫取资源租金。
We suggest a new mechanism to explain political and economic inequality in resource rich countries. The mechanism is based on the premise that migrants are treated less generously in autocracies than in democracies. As a consequence, democracies want fewer migrants than autocracies. After democratization a new government may therefore start out with (potentially many) more migrants than their preferred level. These excess migrants, inherited from the autocracy, represent a costly legacy that makes democracy less attractive to citizens. With democracy less attractive, it is cheaper to compensate citizens for not challenging the autocratic regime. Not only that — by adding even more migrants, democratization becomes even less attractive, enabling the ruler to keep even more of the resource rents for himself without a threat of losing power.