Rise and Fall Dynamics in Empires

Discussion

Peng Lu and Dianhan Chena:

"The rise, development, and decline of empires are affected by many factors.

Taagepera (1995) described the life cycle of the Empire as a flat-topped parabola, which suggests that imperial collapse must be an exceptional event due to exceptional circumstance . In previous studies, regional stability, revolutionary elites, imperial ideologies, abandoned brethren and state capacity are closely related to the imperial collapse .

Olson (2008) believes that the exist of large number of interest groups is a sufficient and necessary condition for imperial collapse [. The climate change is also considered as an important reason for the rise and decline of dynasties. For example, colder temperature led to the decline of Tang and Ming Dynasties, and high atmospheric moisture levels promoted the formation and development of big cities and empires. Besides, economical, financial, reserve currency and geopolitical role, and their relative power are also influential during the rise and fall of Empire .

In sociological fields, the reasonable explanation for the decline mechanism of agricultural empires is probably the demographic-structural theory . Population growth indirectly causes social crisis, by causing economic, political and social problems, which jointly affect social stability . In agricultural empires, the land is the most important resource. Population growth would lead to scarcity of materials, and intensified contradictions within elites, the Asabiya lost, and factional conflicts eventually leading to the collapse . When the growth of population exceeds the growth of land productivity, the systemic problems, such as rising prices, tax increases , and social movements will follow, which undermines affect social institutions and leads to decay of the country . Regarding to the rise-and-fall dynamics, many models were proposed. Collins (1978) proposed the geopolitics theory, focusing on territorial dynamics of empires.

It utilized three mechanisms, such as geopolitical resources, logistical loads, and the marchland position . The digital structural (1995) and ruler legitimacy models (1995) , then perfected this geopolitical model. Some use the sense of collectivity (Asabiya) to demonstrate the relationship between population and resources. Empire’s life cycle is determined by the rise and fall of Asabiya. Turchin (2003) argued that meta-ethnic frontiers is central in promoting Asabiya, and proposed the meta-ethnic frontier model to explain imperial cycles. He also expanded demographic-structural theory, and established Demographic-Fiscal and Elite Cycle models, to discusses the relationship between population density, elite reproduction, extraction ability, and national decline. For history of China, the dynastic cycle is defined as the periodic alternation of societies between autonomy and management.

The demographic structural theory becomes a principal model for China. Some use simple but effective models of bandits, peasants & rulers, to explored dynastic cycles [36, 37]. For Chu and Lee's model (1994), the population growth led to the shortage of resources, and more farmers became bandits. Under a certain scale, they became fatal threats to the rulers, and the regime will decay. Demographic structural theory can be still applied to political stability studies.

For example, Turchin (2010) and Ortmans et al. (2017) use it to predict the political pressures for USA and UK, as well as the factors and patterns of social & political stability worldwide. We apply the collective action model to simulate the empires in China, and the concept of Asabiya connects them both.

In his book, Historical dynamics: Why states rise and fall, Turchin (2003) discussed the similarity between Asabiya (the collective action ability of group) and empire cycles. For collective action, the rise and fall is captured by dynamic number of participants, determined by micro-level individual choices. If more people take part in, it will be stronger. Otherwise, it declines, with more and more people standing by as nonparticipants or free-riders. It also holds for empires where the people live. Full of corruptions and information bias , the empire will decay and die, with more and more people (non-supporters) hating the rulers. More people will become unloyalty, resistant, or uncooperative. For the healthy periods, the empire is with less corruption and information bias, with more and more supportive people who are loyalty to rulers of empire, with Passionarity. For stronger empires, major crisis can be even overcome, with massive supporters. Since 2016, the peak model has been used to explore the life cycle dynamics of collective actions. Hence, this can be also applicable to rise and fall dynamics of Empire. The microlevel mechanism of individuals or agents, under collective actions and empires, are similar to each other. The rise and fall of empires are determined by individuals, the fundamental actors of society. Based on behaviors of micro-level agents, we construct the life cycle model of empires, to simulate real life cycles in history."

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Characteristics

Peng Lu and Dianhan Chena:

"The life cycles (rises and falls) of empires are caused by the following aspects, which have been modeled dynamically:

Social Wealth

(a) Fixed amount of social wealth 𝑽𝒈. For agricultural empires, the amount of social wealth is determined by the area of farmland. Due to the limitation of farmland in empires, the total social wealth is fixed or limited. For all empires in history of China, the fixed size of farmland leads to limited production of grains, limited populations, and limited social wealth. For instance, the total amounts of arable lands (plain) are roughly the same for all dynasties in China;

Population Size

(b) The growing population size (N). The contradiction between man and land plays the biggest role in shaping the life cycle dynamics of empires. Although the social wealth is fixed or limited, the population tends to rebirth and grow, until the end (crash) of empires [28]. According to the Malthus theory of population, only wars, disasters and pandemics can stop the temporary growth of people [76]. The growing population tends to decrease the average payoffs of all individuals, according to equation (2)[46]. Besides, under certain social stratification or power structure, the imparity distribution further dampens this satiation, like the collapse of the Roman Empire [77]. Hence, this deeply-rooted contradiction leads to decays, chaos and declines of empires; and

Governance Capability

(c) The effects of governance capability. The parameter J captures the governance quality of empires. For advanced or successful social governance, the dilution effect of income becomes weaker or more latent, and social cohesion levels is much higher. For instance, we have more people supporting their empires, because successful economic reforms [78] and cultural policies, such as the Confucianism [79, 80], were successfully performed for several times in history. For poor governance, the dilution effect is much stronger, and there were more social members hating their empires."

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