\( \newcommand{\sfrac}{l} \newcommand{\ssfrac}{L} \newcommand{\topop}{\alpha} \newcommand{\mratio}{c} \newcommand{\deq}{:=} \newcommand{\intensity}{h} \newcommand{\fratio}{\gamma} \newcommand{\sdsfrac}{\sfrac^+} \)

Introduction

Assume that a total out-migration curve has been built and that we have a set of migration ratios \(\mratio_\topop^i\) for age interval \([x_i,x_{i+1})\) , where \(\mratio_\topop^i\) is the number of out-migrations to population \(\topop\) divided by the total out-migrations. The objective is to build a destination-specific migration curve. The two main build methods are CONSTANT_RATIO and HYBRID_RATIO. See Multiple Decrement Build Methods for details. The table below gives the BuildMethods currently supported

MultiTransBuildMethod Description
CONSTANT_RATIO Between age nodes the migration ratio is constant. Use this method to interpolate a smooth curve
HYBRID_RATIO Between age nodes the migration intensity is a quadratic function of age. Use this method to interpolate a smooth curve
PSPLINE Smooth migration ratios using P-splines.