偿付能力、生命周期与养老金动态调整策略

本文从生命周期的角度,把养老保险基金的偿付能力作为内生变量,直接引入到养老金调整模型,使之能够自我反馈信息和修正预测偏差,并能根据偿付能力的变化对养老金进行动态调整,最终使养老保障能力与偿付能力实现了内在统一。情景分析表明:(1)在人口出生率和经济增速持续放缓的趋势下,如果不优化当前的养老金调整模式,偿付能力不足的程度将持续加剧;(2)与现行政策和现有模型相比,基于偿付能力构建的调整模型,能有效缓解偿付能力不足的程度,而且降低了养老金大幅波动的风险;(3)结合生命周期理论来调整养老金,不仅偿付能力的提升效果优于其它模式,而且延长了参保人员应对风险的时间,更加符合风险承受能力变化的生命周期特征,提高了抵抗风险的能力;(4)在制定延迟退休年龄等政策时,要综合考虑调整模式、养老金增长率和人口出生率等多方面因素,养老保险基金才可能持久地保持充足的偿付能力。     

The Actuarial Balance Sheet for Pay‐As‐You‐Go Finance: Solvency Indicators for Spain and Sweden*

This paper provides the first estimate of the actuarial balance of the Spanish contributory pension system for the old‐age contingency, based on official data. The main accounting entries are developed from the principles of double‐entry bookkeeping. The novel entry in the balance sheet, entitled the ‘contribution asset’ or ‘hidden asset’, is at the centre of the theoretical discussion. A comparison between the official balance sheet for the Swedish notional account system and our balance sheet for the Spanish contributory pension system is also provided. The main finding is that the Spanish pension system has an insolvency rate of 31.4 per cent. The policy implication is that unless current legislation is reformed, Spanish taxpayers (the plan sponsor) should count on making transfers to the pension system with a present discounted value of 31.4 per cent of current liabilities. Moreover, a comparison of the consecutive balance sheets for 2001‐06 shows that the degree of insolvency is growing over time, even though the cash‐flow outcome has improved over the same period. Taking steps to reverse this trend and restore solvency is in Spanish taxpayers' interest, and possibly also in the interest of those in the European Union who recognise that there is a chance that they may have to support the Spanish budget in the future.     

东亚三国的公共养老金制度改革：名义账户制的应用前景评析

在人口老龄化形势下,东亚国家的老年人口赡养率迅速攀升。如何改革公共养老金制度,建立与人口、经济社会形势相适应的养老保障体系,是摆在这些国家面前的一个难题。本文将比较中国、韩国和新加坡的公共养老制度,探讨名义账户制（NDC）在三国的应用前景。通过分析名义账户制化解各国现实问题的潜在能力,作者认为中国适用名义账户制的可行性最强,新加坡较低,而韩国介于二者之间。     

Pension funds with a minimum guarantee: a stochastic control approach

In this paper we propose and study a continuous-time stochastic model of optimal allocation for a defined contribution pension fund with a minimum guarantee. We adopt the point of view of a fund manager maximizing the expected utility from the fund wealth over an infinite horizon. In our model the dynamics of wealth takes directly into account the flows of contributions and benefits, and the level of wealth is constrained to stay above a “solvency level.” The fund manager can invest in a riskless asset and in a risky asset, but borrowing and short selling are prohibited. We concentrate the analysis on the effect of the solvency constraint, analyzing in particular what happens when the fund wealth reaches the allowed minimum value represented by the solvency level.     

Pension plan solvency and extreme market movements: a regime switching approach

We develop and test a new approach to assess defined benefit (DB) pension plan solvency risk in the presence of extreme market movements. Our method captures both the ‘fat-tailed’ nature of asset returns and their correlation with discount rate changes. We show that the standard assumption of constant discount rates leads to dramatic underestimation of future projections of pension plan solvency risk. Failing to incorporate leptokurtosis into asset returns also leads to downward biased estimates of risk, but this is less pronounced than the time-varying discount rate effect. Further modifying the model to capture the correlation between asset returns and the discount rate provides additional improvements in the projection of future pension plan solvency. This reduces the perceived future risk of underfunding because of the negative correlation between interest rate changes and asset returns. These results have important implications for those with responsibility for balancing risk against expected return when seeking to improve the current poor funding positions of DB pension schemes.     

Pension Benefit Security: A Comparison of Solvency Requirements,a Pension Guarantee Fund,and Sponsor Support

Developed countries apply different security mechanisms in regulation to protect pension benefits: solvency requirements, a pension guarantee fund (PGF), and sponsor support. We compare these mechanisms for a generalized form of hybrid pension schemes. We calculate the expected log return for the beneficiaries, the shortfall probability, that is, the likelihood of the pension payment falling below the promised level and the expected loss given shortfall. Comparing solvency requirements to a pension guarantee system or sponsor support involves trading off risk and return. Additional spending on default insurance reduces the shortfall probability and the expected loss given shortfall but also lowers the probability of high positive returns as are feasible under solvency requirements.     

Integrating corporate ownership and pension fund structures: A general equilibrium approach

This paper studies pension fund design in the context of investment in the debt and equity of a firm. We employ a general equilibrium framework to demonstrate that: (i) the asset location ‘puzzle’ is purely a partial equilibrium phenomenon, conceived in a risk neutral setting, that disappears with the introduction of sufficient risk aversion; (ii) the inability of policy makers to manage an economy with multiple firms yields a mixed equilibrium, where bonds are observed in both taxable and tax-deferred accounts; and (iii) the Pareto-efficient pension plan comprises of a defined benefit plan.     

Die Abgrenzung beitragsbezogener Pensionspläne aus Sicht des Asset-Liability-Managements

As a first step towards establishing models for the asset liability management (ALM) of contribution based pension plans of German pension funds it is important to characterize the essential properties of such plans. It is shown that it is not appropriate to assume an equivalence between such plans and a ?Beitragszusage mit Mindestleistung” (contribution based pension plan with investment guarantee). Although the plans under consideration grant the participation in the asset returns generated by the pension fund, they also guarantee a benefit level. This shows clearly that it is impossible to apply traditional ALM models for defined contribution plans — which in general provide no minimum benefit guarantee — to German pension funds without substantial alterations.     

The Impact of the Automatic Balancing Mechanism for the Public Pension in Japan on the Extreme Elderly

Abstract

Most developed countries are seeking ways to maintain a sustainable social security system. Japan is no exception. The old-age dependency ratio in Japan is currently 35% and is expected to be 74% in 2050. Recently the Japanese government has adopted an automatic balancing mechanism, which gradually reduces the real price of the public pension through a reduction of inflation adjustments. The reduction, depending on future demographics, is a random process, so the elderly, in particular the extreme elderly, have to take the risk of receiving an inadequate public pension. The objectives of this paper are threefold. First, we review the recent trends in Japanese mortality and explain the underlying longevity issues that led to the automatic balancing mechanism. Second, by means of stochastic mortality and fertility modeling, we analyze how demographic changes will affect the future of public pensions in Japan. Third, we demonstrate, on the basis of the stochastic projections we made, how the automatic balancing mechanism will affect the financial security for people who live beyond age 100.     

Pension Valuation Under Uncertainties: Implementation of a Stochastic and Dynamic Monitoring System

Financial soundness and funding stability are two critical issues in pension fund management. First, we construct a generalized stochastic model to monitor the solvency risk and cash flow dynamics of the defined benefit pension plan. A semi‐Markov process proposed by Dominicis et al. (1991) and Janssen and Manca (1997) is employed in structuring the transition pattern of the plan's population, and the economic‐based factors are generated through plausible stochastic processes. Modifications according to classification and movements of the plan member and the plan's turnover pattern are also employed to improve its practical usefulness. Then the actuarial valuations, cash flow analyses, and workforce projection are performed and investigated. Second, we explicitly formulate the plan dynamics and implement the proposed mechanism into a risk management framework for pension management. By employing the stochastic and dynamic approach, the cost factors can be monitored throughout the valuation process. Third, we outline the procedure of implementing the proposed methodology into a monitoring system. Finally, the Taiwan Public Employees Retirement System is simplified to illustrate techniques in achieving risk management goals.     

中国企业年金计划担保机制研究

为顺利推进养老金制度改革、减小职工面对的投资风险、平衡职工间的收益差异,多数国家建立起了以收益率担保为主的DC型企业年金担保机制。我国的企业年金计划也引入了风险准备金制度,但这一绝对收益率担保政策尚存在担保评估周期模糊、担保收益率较低、担保方式和资金来源单一的问题。特别地,在年金基金面临投资亏损、企业(计划发起人)或年金计划破产等担保需求下,当前我国迫切需要进一步完善收益率担保机制并构建破产担保机制。     

Evaluating the Financial Performance of Pension Funds: An Individual Investor's Perspective

Pension funds require the managerial expertise of financial intermediaries, who must be paid a fee or spread. The spread significantly reduces the value of the pension fund over longer holding periods, and implies significantly greater incentive conflicts for defined contribution-funded pension funds than for defined benefit-funded pension funds. The magnitude of the intermediary spread and those factors affecting the demand for financial intermediary reputation and the marginal fee for this reputation are examined for a sample of 66 defined contribution and 54 defined benefit Australian pension funds during 1991–93. The intermediary spread significantly reduces the average net return provided to individual investors, particularly for defined contribution pension funds. Agency-related factors affecting the demand for financial intermediary reputation and its marginal fee reflect underlying contract-based differences between these types of fund.     

What determines corporate pension fund risk-taking strategy?

Corporate sponsors of defined benefit pension plans generally assume low investment risk when they have low funding ratios and high default risk, consistent with the risk management hypothesis. However, for financially distressed sponsors and sponsors that freeze, terminate, or convert defined benefit to defined contribution plans, the risk-shifting incentive (moral hazard) dominates. Pension fund risk-taking is also affected by labor unionization and sponsor incentives to maximize tax benefits, restore financial slack, and justify the accounting choices of pension assumptions. Sponsors shift toward an aggressive risk strategy when their pension plans emerge from underfunding, bankruptcy risk is reduced, or marginal tax rate decreases. Overall, we show that corporate sponsors adopt a dynamic risk-taking strategy in their pension fund investments.     

The Value and Risk of Defined Contribution Pension Schemes: International Evidence

We use historical data on investment returns and labor income from 16 countries to quantify the value and risk of defined contribution pension plans, building frequency distributions of pension fund and pension replacement ratios for each country. We show that pension risk is substantial and find that pension fund ratios are lower and less variable than when the correlation between wage growth and investment returns is ignored, typically halving the median pension fund ratio. We also show that an all‐equity fund is the dominant investment strategy across all countries, although sometimes a life‐cycle strategy insures against downside risk.     

The Role of the Auditor in Modern Society: An Exploratory Essay

This paper examines competing proprietary and political cost arguments for incentives facing managers of different types of Australian and UK pension fund, to voluntarily disclose pension liability information in annual reports sent to their participants. For Australian defined benefit pension funds, the disclosure reveals the fund's actuarial surplus or deficit, which conveys information to participants about the pension fund's ability to generate future cash flows. Tests are conducted on the voluntary reporting practices of a sample of 119 Australian and 100 UK pension funds, using variables which prior research suggests affects their financial valuation and performance. The empirical results support predictions that managerial discretionary disclosure carries proprietary cost implications for Australian defined benefit pension funds, as proxied by their investment risk and funding ratio, and political cost implications for Australian defined contribution and UK defined benefit pension funds, as proxied by their size.     

A new way of looking at the risk in defined benefit pension plans

The portability feature of a defined contribution (DC) pension greatly reduces the risk to the accumulation of pension wealth. Conversely, defined benefit (DB) pensions have a variety of default risks that decrease the expected value of DB pension wealth. This paper examines those risks. Accrual of DB pension wealth is characterized in terms of purchases of risky bonds. Changing jobs triggers default on these bonds. Simulations are presented to show the potential loss in pension wealth from default. In addition, a methodology used to price corporate bonds is applied to generate estimates of the implied risk premiums of DB pension bonds over comparable riskless bonds.     

Defined Benefit or Defined Contribution? A Study of Pension Choices

We solve an empirically parameterized life‐cycle model of consumption and pension choices to show how expected earnings growth and risk affect the benefits of final‐salary defined benefit (DB) pension plans, relative to pension plans that are defined contribution (DC) in nature. We use micro data on the pension choices of individuals to provide evidence consistent with the model predictions: (1) individuals who expect a higher growth rate of earnings are more likely to choose DB final‐salary schemes, and (2) individuals who face a higher variance of persistent income shocks are less likely to choose DB final‐salary schemes. We control for cohort and age fixed effects in the empirical analysis.     

The tax treatment of UK defined contribution pension schemes

The paper aims to clarify the tax status of pension schemes in the UK and, by using economic and other arguments, to establish a theoretical benchmark that could be considered the ‘appropriate’ tax regime for pension saving. We consider existing tax regimes for saving (such as the ‘ISA’ regime) and theoretical regimes (such as a pure expenditure tax and a comprehensive income tax) and we compare the costs different tax regimes impose on defined contribution pension schemes. We conclude that an expenditure tax is an appropriate benchmark tax regime for pension saving, and that other tax regimes impose additional financial as well as administrative costs.     

Iterated VaR or CTE measures: A false good idea?

The purpose of this paper is twofold. Firstly, we consider different risk measures in order to determine the solvency capital requirement of a pension fund. Secondly, we illustrate the impact of the time horizon of long-term guarantee products on these capital. We consider a financial market modelled by a common Black–Scholes–Merton model. We neglect the mortality and underwriting risks by assuming that the pension fund is fully hedged against these risks, which allows us to keep understandable and tractable formulæ (the longevity risk will be a part of future researches). A portfolio is built in this market according to different strategies and the pension fund offers a fixed guaranteed rate on a certain time horizon. We begin with well-known static risk measures (value at risk and conditional tail expectation measures) and then we consider their natural dynamic generalization. In order to be time consistent, we consider their iterated versions by a backward iterations scheme. Within the dynamic setting, we show that solvency capital can be expensive and that attention must be paid to the safety level considered.     

Compulsory Savings: Efficiency and Redistribution On the Interaction of Means Tested Basic Income and Public Pensions

In the presence of means tested basic income for old age, households will tend to reduce precautionary savings to an inefficiently low level. We explore how this might serve as a justification for a compulsory public pension system. In a representative agent framework with two income types, compulsory savings are found to be Pareto-improving up to a point. Beyond that point, increases in contribution rates simply result in increasingly regressive (implicit) taxation. Similar results are found for pay-as-you-go pensions. On the basis of our model we argue that the introduction of a funded pension component may help the German pension system to cope with demographic change more efficiently.