MOSART is a dynamic microsimulation model for education, labour supply and pensions. Microsimulation is a useful method when behaviour is more easily modelled at the individual level, and then aggregated to totals, rather than modelling relations between aggregated variables. This is often the case when behaviour is non-linear and the population heterogenous, blurring the relation between micro and macro. Analyses of tax- and pension-systems are good examples.

MOSART is based on administrative data for the entire Norwegian population back to the 1960s and simulates the further life course for each person. The simulation is carried out by drawing if each person each year makes certain transitions from one state to another with transition probabilities depending on each person’s characteristics. These probabilities are estimated from observed transitions in a recent period. For years with actual observations simulation and transition probabilities are aligned to these. Events like births, deaths, migration, marriages, divorces, educational activities, labour force participation, retirement, income and wealth are included in the simulation. 

The model's main use has been projections and policy analyses regarding the design and evaluation of the Norwegian pension system.

Funder: Ministry of Labour, Ministry of Finance

Publications

A short description of the model:

Andreassen, L., Fredriksen, D., Gjefsen, H.M., Halvorsen, E. and Stølen, N.M. (2020): The dynamic cross-sectional microsimulation model MOSART. International Journal of Microsimulation 13 (1), 97-119.

An older, but still relevant and more detailed, documentation of the model is found here: Fredriksen (1998): Projections of population, education, labour supply and public pension benefits.

Analyses

(for articles and reports in Norwegian see here)

European Commission, Directorate-General for Employment, Social Affairs and Inclusion, Dekkers, G., Halvorsen, E., Kruse, H. et al., Long term projections of pension adequacy in a selection of countries – Report produced in the context of the 2024 pension adequacy report, Publications Office of the European Union, 2024, https://data.europa.eu/doi/10.2767/463317

Stølen, N.M., Fredriksen, D., Hernæs, E. and Holmøy, E. (2020): The Norwegian NDC Scheme: Balancing Risk Sharing and Redistribution. In Holzmann, R., Palmer, E., Palacios, R. and Sacchi, S. (2020): Progress and Challenges of Nonfinancial Defined Contribution Pension Schemes Vol 1. World Bank Group, Washington DC, 119-139.

Halvorsen, E. and A. W. Pedersen (2019): Closing the gender gap in pensions. A microsimulation analysis of the Norwegian NDC pension system, Journal of European Social Policy, 29(1), 130-143, 2019.

Brinch, C. N., D. Fredriksen and O. L. Vestad (2018): Life expectancy and claiming behavior in a flexible pension system, Scandinavian Journal of Economics 120(4): 979-1010.

Fredriksen, D., E. Holmøy, B. Strøm and N.M. Stølen (2017): Fiscal effects of the Norwegian pension reform – A micro-macro assessment. Journal of Pension Economics and Finance.  pp. 1-36.

Fredriksen, D. and N.M. Stølen (2017): Lifetime pension benefits relative to lifetime contributions. International Journal of Microsimulation, Vol 10 (2), pp. 177-207.