A new relational method for smoothing and projecting age-specific fertility rates: TOPALS

Joop de Beer

Volume 24 - Article 18 | Pages 409–454

A new relational method for smoothing and projecting age-specific fertility rates: TOPALS

By Joop de Beer

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Date received:	28 Jul 2010
Date published:	11 Mar 2011
Word count:	10442
Keywords:	age-specific fertility rate (ASFR), Brass model, European Union, model age schedules, population scenario, relational model, smoothing
DOI:	10.4054/DemRes.2011.24.18

Abstract

Age-specific fertility rates can be smoothed using parametric models or splines. Alternatively a relational model can be used which relates the age profile to be fitted or projected to a standard age schedule. This paper introduces TOPALS (tool for projecting age patterns using linear splines), a new relational method that is less dependent on the choice of the standard age schedule than previous methods. TOPALS models the relationship between the age-specific fertility rates to be fitted and the standard age schedule by a linear spline. This paper uses TOPALS for smoothing fertility age profiles for 30 European countries. The use of TOPALS to create scenarios of the future level and age pattern of fertility is illustrated by applying the method to project future fertility rates for six European countries.