Multiple steady statehood: the roles of productive and extractive capacities

This paper proposes a model of statehood, defined as elite extraction of resources from a subject population. Different from most of the existing literature, the size of the subject population evolves endogenously in a Malthusian fashion, and the elite take into account the effects on future population levels when taxing the current population. The elite can spend extracted resources by investing in productive and extractive capacities. Productive capacity increases the size of the pie, while extractive capacity makes it easier for the elite to tax it. Together—but not each on its own—these two types of investment can give rise to multiple steady-state equilibria, such that one steady state has both a higher rate of extraction, and higher population density and output, than the other steady state. The model can also account for a positive empirical relationship between land productivity and state antiquity among countries with relatively late state development.

Bistabilities and domain walls in weakly open quantum systems

Weakly pumped systems with approximate conservation laws can be efficiently described by (generalized) Gibbs ensembles if the steady state of the system is unique. However, such a description can fail if there are multiple steady state solutions, for example, a bistability. In this case domains and domain walls may form. In one-dimensional (1D) systems any type of noise (thermal or non-thermal) will in general lead to a proliferation of such domains. We study this physics in a 1D spin chain with two approximate conservation laws, energy and the zz-component of the total magnetization. A bistability in the magnetization is induced by the coupling to suitably chosen Lindblad operators. We analyze the theory for a weak coupling strength \epsilonϵ to the non-equilibrium bath. In this limit, we argue that one can use hydrodynamic approximations which describe the system locally in terms of space- and time-dependent Lagrange parameters. Here noise terms enforce the creation of domains, where the typical width of a domain wall goes as \sim 1/\sqrt{\epsilon}∼1/ϵ while the density of domain walls is exponentially small in 1/\sqrt{\epsilon}1/ϵ. This is shown by numerical simulations of a simplified hydrodynamic equation in the presence of noise.

Buying First or Selling First in Housing Markets

Housing transactions by moving homeowners take two steps—buying a new house and selling the old one. This paper argues that the transaction sequence decisions of moving homeowners have important effects on the housing market. Moving homeowners prefer to buy first whenever there are more buyers than sellers in the market. However, this congests the buyer side of the market and increases the buyer–seller ratio, further strengthening the incentives of other moving owners to buy first. This endogenous strategic complementarity leads to multiple steady state equilibria and large fluctuations, which are broadly consistent with stylized facts about the housing cycle.