Пенсионные Реформы И Теневой Сектор: Моделирование Поведения Доходных Групп[Pension reforms and the informal sector: modeling of income groups behavior]

We improve and investigate a dynamic model of the behavior of the population of agents belonging to different income groups during the transition from a pay-as-you-go to a mixed pension system. The model is based on the assumption that wealthier participants are characterized by a lower rate of income discount, which actually means an orientation toward a longer planning horizon. It provides a satisfactory approximation of the trajectories observed in Argentina after the pension reform of 1993, which is largely similar to the Russian reform of 2002. The model shows that as income increases, the proportion of representatives of the corresponding income group who prefer to "keep in the shadow" should decrease. This pattern is consistent with observations. The model explains why pension reforms in many countries have resulted in an expansion of the shadow sector. The impact of the minimum pension, the rate of return on pension savings and the retirement age on the levels of participation of different income groups in the pension system is studied.