Individual Pension System (IPS) can be defined as a type of private pension system designed to ensure that individuals earn additional income by which they can maintain their living standards in the future. Individual pension system allows individuals to invest their savings in pension plans usually managed by asset management companies in this area. Contribution payments made by investors in the IPS can be assessed similar to other financial investments. The objective of the study is to guide how the rate of return (effective interest rate) on an IPS investment can be calculated. In this regard, three different approaches, on the issue of how the return analysis of any IPS investment can be done under various assumptions, are presented in the study. No similar study aiming to calculate the rate of return on any IPS investment has been found in the related literature. In the related literature, the generally accepted approach seems to be the analysis of the effectiveness of insurance companies and of the funds they manage. There are many such studies in the related literature like Peker 2016, Kizilgeçit 2014, Karakaya, Kurtaran and Dağlı 2014, Alptekin and Şıklar 2009. It is unlikely that the analyses used in such studies referred above can be used to calculate the rate of return of any IPS investment. Because in an IPS investment; there are millions of unique investment scenarios specific to each IPS investment in terms of the timing of the funds channeled to the system, amount of contribution payments, the percentage of funds in the pension plan, and the disparity of participant-specific funding expenditure cutoffs. For this reason, the approach presented in this study is expected to provide a good example of how the rate of return of any IPS portfolio, which is initiated and developed specifically for each IPS participant, can be calculated at any given time. Therefore, the most important contribution of the study to the related literature is that it designs the return analysis from the viewpoint of the IPS participants. A case analysis on an IPS investor in Turkey was conducted in the study to illustrate how to calculate and interpret the rate of return (effective interest rate) on his/her IPS investment under various assumptions at a given time. The calculation approach presented in the study can be used by the sector experts for the purpose of informing, directing and encouraging their IPS participants. This study focuses on the resolution of a case study, developed by using a real individual IPS participant's data. In this context, three different analyses were carried out, with three different assumptions, in calculating the rate of return on the IPS investment: In the subsection titled Realistic Analysis (Assumption 1), the case was analyzed on 11.04.2018 through a real IPS investment scenario. Accordingly, the participant's annual rate of return was calculated as 15,1062%. For the same case, the average annual inflation rate (consumer price index-CPI) for the corresponding investment period is 8,5785%. Hence the real rate of return for the case was calculated as 6,0119%. Fund performance analysis (Assumption 2) is designed to assess the performance of the insurance company responsible for fund management, particularly from the perspective of IPS participants. Within the framework of the assumptions set for this analysis, the annual rate of return on the date of the analysis is 16.1610%. The annual real rate of return was calculated as 6,9834% taking into account the annual average inflation rate for the investment period. The optimistic analysis (Assumption 3) is designed on the assumption that the IPS participant has obtained the pension on the date of the analysis. As a result of the analysis carried out within the framework of this last assumption, the annual rate of return was calculated as 17,1204%. The real rate of return was calculated as 7,8670%. Within this framework, two types of suggestions can be made to increase the rate of return on any IPS investment: Firstly, the most important potential contributor to the high return on the IPS investment is the performance of the funds comprising the pension plan. Secondly, there may be some actions that will maximize the positive impact of the state contribution on the rate of return. Accordingly, it is expected that the positive impact of the state contribution to the rate of return on IPS investment will reach to the highest level on the dates when the participant is entitled to the upper level through which he/she will be allowed to receive a higher percentage of the accumulated state contribution in the pension plan.

Keywords: Individual Pension System (IPS), Effective Interest Rate, Rate of Return, Case Study.

JEL Classification: G00, G11, G22.