Peruvian highlands. Contradicting the link between the Inca state and dried potato is that other crops such as maize can also be preserved with only sun. Troll also argued that llamas, the Incas' pack animal, can be found in their largest numbers in this very same region. It is worth considering that the maximum extent of the Inca Empire coincided with the greatest distribution of alpacas and llamas. As a third point Troll pointed out irrigation technology as advantageous to the Inca state-building. While Troll theorized environmental influences on the Inca Empire, he opposed environmental determinism, arguing that culture lay at the core of the Inca civilization. Effects of geography on political regimes Numerous scholars have argued that geographic and environmental factors affect the types of political regime that societies develop, and shape paths towards democracy versus dictatorship. The disease environment Daron Acemoglu, Simon Johnson, and James A. Robinson have achieved notoriety for demonstrating that diseases and terrain have helped shape tendencies towards democracy versus dictatorship, and through these economic growth and development. In their book Why Nations Fail, as well as a paper titled The Colonial Origins of Comparative Development: An Empirical Investigation, the authors show that the colonial disease environment shaped the tendency for Europeans to settle the territory or not, and whether they developed systems of agriculture and labor markets that were free and egalitarian versus exploitative and unequal. These choices of political and economic institutions, they argue, shaped tendencies to democracy or dictatorship over the following centuries. Factor endowments In order to understand the impact and creation of institutions during early state formation, economic historians Stanley Engerman and Kenneth Sokoloff examined the economic development of the Americas during colonization. They found that the beginnings of the success or failure of American colonies were based on the specific factor endowments available to each colony. These endowments included the climate, soil profitability, crop potential, and even native population density. Institutions formed to take advantage of these factor endowments. Those that were most successful developed an ability to change and adapt to new circumstances over time. For example, the development of economic institutions, such as plantations, was caused by the need for a large property and labor force to harvest sugar and tobacco, while smallholder farms thrived in areas where scale economies were absent. Though initially profitable, plantation colonies also suffered from large dependent populations over time as slaves