Introduction

Modgen is a microsimulation model development package developed by and distributed through Statistics Canada. It was designed to ease the creation, maintenance, and documentation of microsimulation models without the need for advanced programming skills as a prerequisite. It accommodates many different model approaches (continuous or discrete time, case-based or time-based, general or specialized, etc.) Modgen also provides a common visual interface for each model that implements useful functionality such as scenario management, parameter input, the display of output tables from a model run, graphical output of individual biographies, and the display of detailed Modgen-generated model documentation.

In this discussion we introduce a simple microsimulation model called RiskPaths that has been implemented using Modgen. We start with a description of its underlying statistical models and then explore follow-up questions, such as what microsimulation can add to the initial statistical analysis and what other benefits microsimulation can bring to the overall analysis. We then demonstrate parts of Modgen's visual interface to examine elements of the RiskPaths model.

RiskPaths can be used as a model to study childlessness and was developed for training purposes. Technically, RiskPaths is a demographic single sex (female only), data-driven, specialized, continuous time, case-based, competing risk cohort model. It is based on a set of piecewise constant hazard regression models.

In essence, RiskPaths allows the comparison of basic demographic behaviour before and after the political and economic transitions experienced by Russia and Bulgaria around 1989. Its parameters were estimated from Russian and Bulgarian data of the Generations and Gender Survey conducted around 2003/04. Russia and Bulgaria comprise interesting study cases since both countries, after the collapse of socialism, underwent the biggest fertility declines ever observed in history during periods of peace. Furthermore, demographic patterns were very similar and stable in socialist times for both countries, which helps to justify the use of single cohorts as a means of comparison (one representing life in socialist times, the other the life of a post-transition cohort). In this way, the model allows us to compare demographic behaviour before and after the transition, as well as between the two countries themselves.