Hans Gersbach

The Long-Run Economic Costs of AIDS: Theory and an Application to South Africa

Most existing estimates of the macroeconomic costs of AIDS, as measured by the reduction in the growth rate of gross domestic product, are modest. For Africa-the continent where the epidemic has hit the hardest-they range between 0.3 and 1.5 percent annually. The reason is that these estimates are based on an underlying assumption that the main effect of increased mortality is to relieve pressure on existing land and physical capital so that output per head is little affected. The authors argue that this emphasis is misplaced and that, with a more plausible view of how the economy functions over the long run, the economic costs of AIDS are almost certain to be much higher. Not only does AIDS destroy existing human capital, but by killing mostly young adults, it also weakens the mechanism through which knowledge and abilities are transmitted from one generation to the next. The children of AIDS victims will be left without one or both parents to love, raise, and educate them. The model yields the following results. In the absence of AIDS, the counterfactual benchmark, there is modest growth, with universal and complete education attained within three generations. But if nothing is done to combat the epidemic, a complete economic collapse will occur within three generations. With optimal spending on combating the disease, and if there is pooling, growth is maintained, albeit at a somewhat slower rate than in the benchmark case in the absence of AIDS. If pooling breaks down and is replaced by nuclear families, growth will be slower still. Indeed, if school attendance subsidies are not possible, growth will be distinctly sluggish. In all three cases, the additional fiscal burden of intervention will be large, which reinforces the gravity of the findings.

Bargaining Power and Equilibrium Consumption

We examine how a shift of bargaining power within households operating in a competitive market environment affects equilibrium allocation and welfare. If price effects are sufficiently small, then typically an individual benefits from an increase of bargaining power, necessarily to the detriment of others. If price effects are drastic, the welfare of all household members moves in the same direction when bargaining power shifts, at the expense (or for the benefit) of outside consumers. Typically a shift of bargaining power within a set of households also impacts upon other households. We show that each individual of a sociological group tends to benefit, if he can increase his bargaining power, but suffers if others in his group do the same.

Democratic Provision of Divisible Public Goods

In this paper we examine the potential of democratic constitutions for the provision of divisible public goods in a large economy. Our main insights are as follows: When aggregate shocks are absent, the combination of the following rules yields first-best allocations: a supermajority rule, equal taxation, exemption of the agenda setter from taxation, and a ban on subsidies. In the presence of aggregate shocks to benefits or to costs of public-good provision, tax-sensitive majority rules, where the size of the required majority depends on the aggregate tax revenues, yield first-best allocations if a monotonicity condition is met. Finally, we explore the potential of first-best constitutions to induce voluntary participation by compensating agents belonging to the minority.

On the Negative Social Value of Central Banks' Knowledge Transparency

We examine to what extent central banks should release their internal assessments concerning the links between money growth and future inflation, and between employment and inflation. We show that the social value of knowledge transparency concerning real shocks is negative since the disclosure of the central banks private information eliminates the possibility of insuring the public against those shocks. Finally, we discuss a number of further arguments which have to be taken into account before policy conclusions can be drawn. Copyright Springer-Verlag Berlin Heidelberg 2003

External spillovers, internal spillovers and the geography of production and innovation

We consider a three-location duopoly model such that (i) firms choose production and innovation locations before (Bertrand) competition takes place and (ii) there are internal and external knowledge spillovers. We show: (1) agglomerations where firms earn negative profits may exist when there are both external and internal knowledge spillovers; (2) greater external spillovers do not necessarily favor agglomeration; (3) decreasing communication costs tend to favor agglomeration; (4) there are exactly two types of agglomeration equilibria: either both firms innovate in the agglomeration, or there is an innovator and an imitator; and (5) if there is a location where both firms produce, then innovation must take place in this location.

Collective Decisions and Competitive Markets

In a general equilibrium model, we allow for households with several, typically heterogeneous, members; households that make (efficient) collective consumption decisions where different households may use different collective decision mechanisms; yet households that operate within a competitive market environment. The interaction of two allocation mechanisms, collective decisions and competitive markets, is investigated, with a focus on the efficiency properties and decentralization possibilities of the dual allocation mechanism.

Promoting Product Market Competition to Reduce Unemployment in Europe: An Alternative Approach?

In this paper, we employ general equilibrium reasoning to review whether product market reforms could help to reduce unemployment in Europe. We consider three potential effects of product market reforms: lowering markups, fostering productivity gains and inducing a more rapid expansion of the product mix. We argue that product market reforms will help to reduce unemployment under most circumstances. Productivity improvements will increase aggregate unemployment only if workers are immobile and unemployment is concentrated in a few sectors. Employment effects remain positive or are even reinforced if wage adjustments occur. Using recent industry studies, we suggest that product market reforms can reduce unemployment significantly, but labor market reforms remain unavoidable nevertheless. Copyright 2000 by WWZ and Helbing & Lichtenhahn Verlag AG

Child Labor and the Education of a Society

We examine economic growth, inequality and education when the wellspring of growth is the formation of human capital through a combination of the quality of child-rearing and formal schooling. The existence of multiple steady states is established, including a poverty trap, wherein children work full-time and no human capital accumulation takes place, with continuous growth at an asymptotically steady rate as an alternative. We show that a society can escape from the poverty trap into a condition of continuous growth through a program of taxes and transfers. Temporary inequality is a necessary condition to escape in finite time, but long-run inequalities are avoidable provided sufficiently heavy, but temporary taxes can be imposed on the better-off. Programs aiming simply at high attendance rates in the present can be strongly non-optimal.

Designing democracy: Ideas for better rules

Incentive Contracts and Elections.- Overview.- Unobservability and Short-Termism in Long-Term Policies.- Short-Termism and Competition for Incentive Contracts.- Reelection Thresholds.- Effort Incentives and Monetary Rewards.- Limits to Incentive Contracts in Politics.- Rules for Decision-Making and Agenda Setting.- Overiview.- Examples for Agenda Rules.- Flexible Majority Rules.- Democratic Mechanisms.- Fair Division.

Firm Defaults and the Correlation Effect

We examine how the correlations of bank loan defaults depend on the correlations of asset returns and how correlations and diversification are affected by macroeconomic risks. We highlight the main properties of the relationship between asset returns and default correlations, illustrating how adverse macroeconomic shocks raise not only the likelihood of defaults, but also the correlation of defaults. The latter effect, called correlation effect, may account for more than 50% of the increase in the credit risk.