Modelling the participation function with a one-parameter family of cubic splines


Ken J Harrison, Rob J Hyndman


19 May 2015

Publication details

Report to ACTAC ITI technical committee



We suggest that a simple one-parameter family of cubic spline functions would serve quite adequately as models of the participation curve that is the key component of ITI calculations. This would remove the subjectivity associated with the use of two-parameter logistic functions, and would allow all states to use the same method for ITI calculations.