Model Migration Schedules: Three Alternative Linear Parameter Estimation Methods

Abstract

Observed schedules of migration rates exhibit strong regularities in age patterns. These regularities may be captured and represented by a mathematical expression known as the multiexponential model migration schedule. Fitting this function to empirical data requires non-linear regression methods and often some experimentation with alternative initial estimates of the parameters. Simpler, linear methods of estimation are adequate for most applications. These may be carried out with hand calculators or simple spreadsheet-based calculations on the computer. Such methods are studied and appear to perform satisfactorily.