Graduate School of Environmental Sciences, Hokkaido University, Sapporo, Japan ; Programa de Investigación en Enfermedades Tropicales (PIET), Escuela de Medicina Veterinaria, Universidad Nacional, Heredia, Costa Rica ; Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
PLoS One. 2013 Dec 20;8(12):e82863. doi: 10.1371/journal.pone.0082863. eCollection 2013.
Land tenure inequity is a major social problem in developing nations worldwide. In societies, where land is a commodity, inequities in land tenure are associated with gaps in income distribution, poverty and biodiversity loss. A common pattern of land tenure inequities through the history of civilization has been the formation of latifundia [Zhuāngyuán in chinese], i.e., a pattern where land ownership is concentrated by a small fraction of the whole population. Here, we use simple Markov chain models to study the dynamics of latifundia formation in a heterogeneous landscape where land can transition between forest, agriculture and recovering land. We systematically study the likelihood of latifundia formation under the assumption of pre-capitalist trade, where trade is based on the average utility of land parcels belonging to each individual landowner during a discrete time step. By restricting land trade to that under recovery, we found the likelihood of latifundia formation to increase with the size of the system, i.e., the amount of land and individuals in the society. We found that an increase of the transition rate for land use changes, i.e., how quickly land use changes, promotes more equitable patterns of land ownership. Disease introduction in the system, which reduced land profitability for infected individual landowners, promoted the formation of latifundia, with an increased likelihood for latifundia formation when there were heterogeneities in the susceptibility to infection. Finally, our model suggests that land ownership reforms need to guarantee an equitative distribution of land among individuals in a society to avoid the formation of latifundia.
土地所有权不平等是全球发展中国家的一个主要社会问题。在以土地为商品的社会中，土地所有权的不平等与收入分配差距、贫困和生物多样性丧失有关。文明史上土地所有权不平等的一个常见模式是大庄园的形成，即土地所有权集中在少数人口手中。在这里，我们使用简单的马尔可夫链模型来研究在一个异质景观中土地所有权不平等的形成动态，其中土地可以在森林、农业和恢复土地之间进行转换。我们在假设前资本主义贸易的情况下，系统地研究了大庄园形成的可能性，在这种贸易中，贸易是基于属于每个个体土地所有者的土地地段在离散时间步长内的平均效用。通过将土地交易限制在恢复过程中，我们发现大庄园形成的可能性随着系统的大小（即社会中的土地和个体数量）的增加而增加。我们发现，土地利用变化的转变率（即土地利用变化的速度）的增加促进了土地所有权更公平的模式。系统中引入的疾病降低了受感染个体土地所有者的土地盈利能力，促进了大庄园的形成，当感染易感性存在异质性时，大庄园形成的可能性增加。最后，我们的模型表明，土地所有权改革需要确保社会中个体之间土地的公平分配，以避免大庄园的形成。
