Using proxies for the short rate: when are three months like an instant?

The dynamics of the unobservable short rate are frequently estimateddirectly using a proxy. We examine the biases resulting fromthis practice (the 'proxy problem'). Analytic results show thatthe proxy problem is not economically significant for single-factoraffine models. In the two-factor affine model of Longstaff andSchwartz (1992), the proxy problem is only economically significantfor pricing discount bonds with maturities of more than fiveyears. We also describe two different numerical procedures forassessing the magnitude of the proxy problem in a general interestrate model. When applied to a nonlinear single-factor model,they suggest that the proxy problem can be economically significant.     

The macrodynamics of international migration as a socio-cultural diffusion process. Part B: applications

"This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin....Two specific paradigms of diverse nature serve to demonstrate the model's tenets and pertinence, one being Greek emigration to the United States since 1820, and the other total out-migration from Cyprus since statehood (1946)."     

The macrodynamics of international migration as a sociocultural diffusion process. Part A: theory

"This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin." The author tests the model using data on Greek emigration to the United States since 1820 and on total emigration from Cyprus since 1946.