The MicSim Package of R: An Entry-Level Toolkit for Continuous-Time Microsimulation

High entry barriers might discourage many social scientists from using existing microsimulation software. This article presents the functionality and capabilities of the free and open source R package MicSim which allows performing continuous-time microsimulation at a very fine-grained level from a low level entry point. Hence, the package might also be of interest to people who are new to R. The package implements a generic microsimulation model for a wide range of demographic applications. Its central device is the individual life-course, which is defined by the sequence of states the individual visits over time and the intervals between the transitions from one state to another. The MicSim model is by design a discrete-event simulation model in which a demographic event implies a change in the state of an individual. The considered population is open and life-courses are specified to evolve along three continuous time scales: individual age, calendar time, and the time that an individual has already spent in the current state. The stochastic model of the microsimulation is parameterized with a base population, transition rates, and (if applicable) a population of migrants. Besides stochastic events, the package allows specifying deterministic events such as enrolment of children in elementary school. Example applications illustrate the capabilities of the package.