The transition to a multi-pillar pension system: the inherent socio-economic anomaly
Authors: Wolf Ishay , Caridad y Ocerin Jose Maria 
Published: February 2021

Purpose
This paper aims to analytically show that in an over-lapping-generation (OLG) model, low earning cohorts bear unwanted risk and absorb higher economic cost than high earning cohorts do.

Design/methodology/approach
This paper aims to consider the individual's risk appetite, using a simple utility function, based on consumptions and discount rates in each period. This paper calibrates the model according to teh Israeli pension system as a representative of a small open developed organization for economic cooperation and development country. Israel is considered as unique case study in the pension landscape, as it implements almost pure defined contribution pension scheme with continuous trend of pension market capitalization (Giorno and Jacques, 2016). Hence, this study finds Israel suitable for examining the theoretical mix of pension scheme. That model enables exploring combined solutions for adequate old age benefits, involving the first and the second pension pillars, under fiscal constraints.

Findings
It comes out that for risk-averse individuals, the optimal degree of funding is negatively correlated to asset returns' volatility and positively correlated to earning decile level. The neglect of risk and individual's current earning level will thus overstate the contribution level and funded percentage from total contributions. Moreover, even in an economy with minimum government intervention, and highly developed private pension fund with high average of rate of return, the authors find it is optimal that the pension system contains a sizeable unfunded pillar. This paper innovates by revealing a socio-economic anomaly in design of mix pension systems in favor of high earning cohorts on the expense of economic loss of low earning cohorts.

Practical implications
The model presented in this paper could be implemented in countries with mix pension systems, as an alternative to public social transfers or means tested, alleviating poverty and inequality in old age. Additionally, this model could raise the public awareness of the financial sustainability of the unfunded pay-as-you-go pillar to diversify financial risk in pension systems, especially for low earning cohort in society.

Social implications
One area of research that is particularly relevant in this context concerns the issue of alleviating poverty and income inequality. It is often stressed that the prevention of old age poverty is among the central targets of well-designed pension system (Holzmann and Hinz, 2005). The conceptualization of minimum pension guarantee used in this composition allows to clearly capturing the notion of such a poverty and social targets as an integral part of the pension system rolls.

Originality/value
This paper innovates by revealing a socio-economic anomaly in design of mix pension systems in favor of high earning cohorts on the expense of economic loss of low earning cohorts. That comes to realize through the level of total contribution rates and funded share that are generally optimal for high earning cohorts but not for low earning cohorts. This paper identifies that the effect of anomaly is most significant in a market characterized with high income-inequality level. This paper finds that imposing intra-generational risk sharing instrument in the form of minimum pension guarantee can re-balance pension design among different earning cohorts. This solution demonstrates balancing effect on the entire economy.