Political Dynasties
研究美国国会中政治王朝的普遍性，发现政治权力具有自我延续性：议员掌权时间越长，其亲属未来进入国会的可能性越大，表明政治精英的固化并非仅因能力差异。
Political dynasties have long been present in democracies, raising concerns that inequality in the distribution of political power may reflect imperfections in democratic representation. However, the persistence of political elites may simply reflect differences in ability or political vocation across families and not their entrenchment in power. We show that dynastic prevalence in the Congress of the U.S. is high compared to that in other occupations and that political dynasties do not merely reflect permanent differences in family characteristics. On the contrary, using two instrumental variable techniques we find that political power is self-perpetuating: legislators who hold power for longer become more likely to have relatives entering Congress in the future. Thus, in politics, power begets power.