Designing social security - a portfolio choice approach

Public social security systems may provide diversification of risks to individuals’ life-time income. Capturing that a pay-as-you-go system (paygo) may be considered as a “quasi-asset”, we study the optimal size of the paygo system as well as the optimal split between funded and unfunded pension saving by means of a theoretical portfolio choice framework. A low-yielding paygo system can benefit individuals if it contributes to hedge other risks to their lifetime resources. Numerical calculations indicate that optimal social security systems should be at least partly paygo financed in many economies. The optimal magnitude of the paygo system depends on the specified risk concept as well as the stochastic properties of stock market returns and implicit paygo-returns.     

Institutions,quality competition and public service provision: The case of public education

This paper contributes to the literature on integovernmental competition in two ways. First, the institutional setting within which public services are delivered is analyzed with respect to the impact on the quality of services provided. Previous studies have measured competition only in terms of governmental structure, ignoring the issue of service quality and the potential for differentiating local governmental jurisdictions along quality dimensions. Second, the outcome of competition is defined in terms of service quality. Previous studies generally have measured the outcome of competition by examining the fiscal effects of fragmentation and accountability through service costs or tax revenue impacts. School districts were used to empirically test quality competition. Student academic performance was modeled as a function of control variables and the degree of competition from neighboring school districts. Academic performance in public schools was positively associated with the performance of neighboring districts, although the effect was small. These findings, however, suggest that strategies to strengthen interjurisdictional competition may be useful in enhancing public service quality.     

Public goods in networks

This paper considers incentives to provide goods that are non-excludable along social or geographic links. We find, first, that networks can lead to specialization in public good provision. In every social network there is an equilibrium where some individuals contribute and others free ride. In many networks, this extreme is the only outcome. Second, specialization can benefit society as a whole. This outcome arises when contributors are linked, collectively, to many agents. Finally, a new link increases access to public goods, but reduces individual incentives to contribute. Hence, overall welfare can be higher when there are holes in a network.     

Rawlsian pricing of access to public facilities: A unidimensional illustration

We consider a setting where citizens using a public facility face an idiosyncratic private access cost and must also contribute to the costs of facility. We show that if the population is uniformly spread over the real line, the cost of a facility is independent of location and access costs are linear in distance, the Rawlsian access pricing is the unique cost sharing solution that satisfies the “core property” of secession-proofness. The latter amounts to the voluntary participation principle under which no group of citizens should be charged more than the cost incurred if it had acted on its own.     

Education, Work and Wages in the UK

Abstract. This paper is concerned with the relationship between education, wages and working behaviour. The work is partly motivated by the sharp distinction in the literature between the returns to education and the effect of wages on labour supply. Education is the investment that cumulates in the form of human capital while labour supply is the utilization rate of that stock. Yet, variation in education is usually the basis for identifying labour supply models – education is assumed to determine wages but not affect labour supply. Moreover, it is commonly assumed that the private rate of return to education can be found from the schooling coefficient in a log-wage equation. Yet, the costs of education are largely independent of its subsequent utilization but the benefits will be higher the greater the utilization rate. Thus the returns will depend on how intensively that capital is utilized and we would expect that those who intend to work least to also invest least in human capital. Indeed, the net (of tax liabilities and welfare entitlements) return to education will be a complex function of labour supply and budget constraint considerations.
Here we attempt to model the relationship between wages, work, education and the tax/welfare system allowing for the endogeneity of education as well for the correlations between the unobservable components of wages and working behaviour. We use the estimates to simulate the effect of a new UK policy designed to increase education for children from low-income households.     

Performance rating and yardstick competition in social service provision

This paper investigates whether national evaluation of decentralised government performance tends, by lessening local information spill-overs, to reduce the scope for local performance comparisons and consequently to lower the extent of spatial auto-correlation among local government expenditures. It analyses local government expenditures on personal social services in the UK before and after the introduction of a national performance assessment system (SSPR, Social Services Performance Rating) that would attribute a rating to each local authority. The empirical evidence is consistent with the hypothesis that the SSPR has reduced local yardstick competition.     

Contest architecture

A contest architecture specifies how the contestants are split among several sub-contests whose winners compete against each other (while other players are eliminated). We compare the performance of such dynamic schemes to that of static winner-take-all contests from the point of view of a designer who maximizes either the expected total effort or the expected highest effort. For the case of a linear cost of effort, our main results are: (1) If the designer maximizes expected total effort, the optimal architecture is a single grand static contest. (2) If the designer maximizes the expected highest effort, and if there are sufficiently many competitors, it is optimal to split the competitors in two divisions, and to have a final among the two divisional winners. Finally, if the effort cost functions are convex, the designer may benefit by splitting the contestants into several sub-contests, or by awarding prizes to all finalists.     

Testing for Seasonal Fractional Roots in German Real Output

Abstract. This paper examines the seasonal structure of German real GNP per capita by using a version of Robinson's (1994) tests which is suitable in the context of seasonality. This method has several advantages over alternative approaches when testing for seasonal unit roots. First, unlike standard tests, which are nested in AR alternatives, it is embedded in fractional alternatives. Second, it allows testing at the zero frequency and at each of the seasonal frequencies separately. Third, it makes it possible to test for different orders of integration at each of the frequencies simultaneously. The empirical analysis suggests that the real output series may have a unit root at the zero frequency, and fractional rather than unit roots at the seasonal ones. This is in contrast to the findings reported by Lutkepohl et al. (1999) in their study on German money demand, and shows the importance of modelling the seasonal features of the data in alternative ways.     

A general equilibrium analysis of software development: Implications of copyright protection and contract enforcement

We develop a general equilibrium model to study the implications of a legal environment on the organization of software production. We show that contract enforcement determines the organizational mode (i.e., in-house versus outsourcing) of customized software development while copyright protection affects both packaged software as well as customized software development. We obtain some testable results: when copyright protection is weak, only customized software will be developed; when copyright protection is strong, both customized software and packaged software will be developed; environment changes in one software market affect the equilibrium in the other software market.     

Mean-variance hedging for interest rate models¶with stochastic volatility

The mean-variance hedging approach for pricing and hedging claims in incomplete markets was originally introduced for risky assets. The aim of this paper is to apply this approach to interest rate models in the presence of stochastic volatility, seen as a consequence of incomplete information. We fix a finite number of bonds such that the volatility matrix is invertible and provide an explicit formula for the density of the variance-optimal measure which is independent of the chosen times of maturity. Finally, we compute the mean-variance hedging strategy for a caplet and compare it with the optimal stategy according to the local risk minimizing approach. Received: 14 July 2000 / Accepted: 10 April 2001