In the late ninth century, rural settlement, agriculture, and urbanization all collapsed in southern Mesopotamia. We first document this collapse using newly digitized archaeological data. We then present a model of hydraulic society that highlights the collapse of state capacity as a proximate cause of the collapse of the economy and a shortened horizon of the ruler as a potential driver of the timing of the collapse. Using cross sections of tax collection data for 27 districts in southern Mesopotamia in 812, 846, and 918, we verify that the proximate cause of the crisis was the collapse in state capacity, which meant that the state no longer maintained the irrigation system. A particularly destructive succession struggle, shortening the investment horizon of rulers, determined the timing of the crisis.

在 9 世纪后期，美索不达米亚南部的农村定居点、农业和城市化都崩溃了。我们首先使用新的数字化考古数据记录了这次坍塌。然后，我们提出了一个水力社会模型，该模型强调了国家能力的崩溃是经济崩溃的直接原因，而统治者的视野缩短是崩溃时间的潜在驱动因素。使用 812、846 和 918 年美索不达米亚南部 27 个地区的税收数据的横截面，我们验证了危机的直接原因是国家能力的崩溃，这意味着该州不再维持灌溉系统。一场特别具有破坏性的继任斗争缩短了统治者的投资视野，决定了危机的时机。