They applied the “Page 99 Test” to their new book, The Evolution of a Nation: How Geography and Law Shaped the American States, and reported the following:
The Evolution of a Nation argues that geography and colonial legal conditions played critical roles in shaping state legislatures and state courts. State geographic characteristics including temperature, rainfall, and access to navigable rivers, lakes, and oceans influenced the occupations of the wealthiest men in a state in 1860. Page 99 describes the share of state wealth held by these state elites. These men had considerable control over who represented their county in state legislatures. In some states the elites were largely agricultural or largely trade-based, and in other states they had a mix of occupations. We show that when elites had similar occupations, a single party tended to control the state legislature, whereas when elites had different occupations, the level of political competition in the legislature was higher. What is striking is that the occupational composition of elites in 1860 is an important predictor of political competition in state legislatures over the period 1866-2000.Learn more about The Evolution of a Nation at the Princeton University Press website.
Colonial legal systems influenced the balance of power between state legislatures and state courts. There are two major legal families: common law and civil law. England has a common-law legal system, while France and Spain have civil-law legal systems. These systems have very different visions of the appropriate balance of power between the legislature and the judiciary. In common law, the judiciary and the legislature are relatively more equal, whereas in civil law the judiciary is explicitly subordinate to the legislature. Because of their colonial heritage, thirteen states had operational civil-law legal systems during the eighteenth or nineteenth century. All of these states except for Louisiana adopted common law around the time of statehood. We show that individuals with civil-backgrounds were politically active during the period in which the balance of power was likely to have been established. Data on judicial retention procedures, the adoption of intermediate appellate courts, and court funding are consistent with these states having different early balances of power. The judiciary in former civil-law states were more easily removed, more heavily monitored, and less well funded, suggesting that they are on average more subordinate than their counterparts in states that always had common law. These differences persisted over the period 1866-2000.
We conclude that geography and colonial legal systems played early and enduring roles in shaping political and legal institutions in the American states. The last chapter examines the effect of state political and legal institutions on state income per capita.
The first chapter, which contains a more detailed description of the book, is available for free at the publisher's website.