Comparative analysis of financial stability of DB-PAYG and NDC plans in Social Security Organization's taieen taklif retirements by systems dynamics approach

Considering the important role of pension funds in creating economic, political, cultural security, etc., paying attention to their financial behavior has a particular importance. Estimating the number and cost of long-term obligations of pensioners of the social security organization and how it is financially sustainable by changing the pension payment scheme of the Taieen taklif law to formal definite participation is one of the objectives of this research. In this research, in accordance with Sterman's methodology, the interactions of the relevant components in the framework of systems dynamics were investigated, and the model was validated using the data of the above organization in 2016-2021. Based on the findings of this research, assuming the continuation of the existing conditions, the number of retirees and their survivors and, accordingly, the future costs of the organization will increase significantly. Also, by changing the pension payment plan in the implementation of the above law to the formal definite participation plan, savings amounted to 1982 thousand billion rials will be created for the organization in the 35 years studied (based on the minimum wage in 1400). According to the results, the new plan is more successful than the current plan in ensuring financial stability and intergenerational justice, but considering the country's economic conditions (annual inflation and low employment rate), it is not recommended for other types of retirement.