Annexation or Conquest? The Economics of Empire Building

This paper develops an economic theory of empire building. This theory addresses the choice among three strategies that empire builders historically have used. We call these strategies Uncoerced Annexation, Coerced Annexation, and Attempted Conquest. The theory shows how the choice among these strategies depends on such factors as the economic gains from imperial expansion, the relative effectiveness of imperial armies, the costs of projecting imperial military power, and liquidity constraints on financing imperial armies. This theory also addresses the scope of imperial ambitions. The paper uses examples from the history of the Roman, Mongol, Ottoman, and Nazi German empires to illustrate the applicability of the theory.

Generalized hydrodynamics of a dilute finite-sized particles suspension: Dynamic viscosity

We present a mesoscopic hydrodynamic description of the dynamics of colloidal suspensions. We consider the system as a gas of Brownian particles suspended in a Newtonian heat bath subjected to stationary non-equilibrium conditions imposed by a velocity field. Using results already obtained in previous studies in the field by means of a generalized Fokker-Planck equation, we obtain a set of coupled differential equations for the local diffusion current and the evolution of the total stress tensor. We find that the dynamic shear viscosity of the system contains contributions arising from the finite size of the particles.Comment: To appear in Physical Review