Policy uncertainty,symbiosis, and the optimal fiscal and monetary conservativeness

This paper extends a well-known macroeconomic stabilization game between monetary and fiscal authorities developed by Dixit and Lambertini (American Economic Review 93: 1522–1542) to multiplicative (policy) uncertainty. We find that even if fiscal and monetary authorities share a common output and inflation target (i.e., the symbiosis assumption), the achievement of the common targets is no longer guaranteed; under multiplicative uncertainty, in fact, a time consistency problem arises unless policymakers’ output target is equal to the natural level.     

Time and uncertainty in resource dilemmas: equilibrium solutions and experimental results

Most common pool resource (CPR) dilemmas share two features: they evolve over time and they are managed under environmental uncertainties. We propose a stylized dynamic model that integrates these two dimensions. A distinguishing feature of our model is that the duration of the game is determined endogenously by the users’ collective decisions. In the proposed model, if the resource stock level below which the irreversible event occurs is known in advance, then the optimal resource use coincides with a unique symmetric equilibrium that guarantees survival of the resource. As the uncertainty about the threshold level increases, resource use increases if users adopt decision strategies that quickly deplete the resource stock, but decreases if they adopt path strategies guaranteeing that the unknown threshold level is never exceeded. We show that under relatively high uncertainty about resource size, CPR users frequently implement decision strategies that terminate the game immediately. When this uncertainty is reduced, they maintain a positive resource level for longer durations.     

Resource-grabbing by status-conscious agents

We introduce a dynamic model of resource-grabbing by status-conscious agents, i.e., agents value not only their absolute consumption levels, but also the relative status within their reference group. We explore the effect of the concern for relative consumption on the growth rate and the welfare of an economy where agents appropriate from a common property resource. Our model shows that the greater is agents' concern about their relative status, the more aggressively they tend to behave. Consequently, social welfare is lower because the growth rate of the public asset is reduced due to higher extraction rate. We also consider the effect of increased heterogeneity, and show that social welfare decreases as the distribution of status-consciousness among agents widens.     

The material basis of the global economy: Worldwide patterns of natural resource extraction and their implications for sustainable resource use policies

Material flow accounting and analysis (MFA) has been established as an influential framework for quantifying the use of natural resources by modern societies. So far, however, no reference data for overall scale and trends of global extraction of natural resources and their distribution between different world regions has been available. This paper presents the first comprehensive quantification of the material basis of the global economy, i.e. used domestic extraction in a time series from 1980 to 2002. We analyse time trends for major material groups (fossil fuels, metals, industrial and construction minerals, and biomass) disaggregated into seven world regions. This allows for (a) an illustration of the global economy's physical growth driven by worldwide processes of economic integration over the past decades, and (b) an indication of the worldwide distribution of environmental pressures associated with material extraction. The results show that annual resource consumption of the world economy increased by about one third between 1980 and 2002. This indicates that scale effects due to economic growth more than compensated for other effects, such as the relative increase of the service sectors' contribution to GDP (structural effect) and the use of new production technologies with higher material and energy efficiency (technology effect). The observed growth of natural resource extraction is unevenly distributed over the main material categories, with metals showing the highest growth rate. The regional analysis shows the increasing importance of Asia and Latin America in global resource extraction. On the global level, material intensity, i.e. resource extraction per unit of GDP, decreased by about 25%, indicating relative decoupling of resource extraction from economic growth. The paper concludes with policy recommendations for a more sustainable use of natural resources.     

Ambiguity and Accident Law

Environmental accidents often involve ambiguous risks, i.e., the relevant probabilities are unknown. This paper studies how liability rules are affected by ambiguity. The injurer and the victim choose a level of care, which is observable, and an unobservable action. Both actions may affect the size and/or likelihood of loss. We analyze the welfare implications of tort rules. First, we show that with ambiguity, negligence is likely to perform better than strict liability. Second, we propose a tort rule of negligence and punitive damages, which gives the efficient levels of both care and unobserved actions.     

Cost Uncertainty and Unilateral Abatement

Unilateral abatement is sometimes advocated in order to set a good example that will make other countries follow. The aim of this paper is to investigate whether existence of correlated cost uncertainty provides an incentive for a country to undertake unilateral abatement. The theoretical model is driven by two main mechanisms; first, a learning effect, as the follower country might reduce its risk premium as it can observe the cost level in the leader country. Second, there is the public good effect, i.e., the marginal benefit of abatement declines when abatement is a public good and other countries contribute to pollution reductions. Results shows that unilateral abatement would be efficient in reducing uncertainty about the unit costs of abatement if a country with low cost uncertainty would undertake abatement first, while a country with initially high cost uncertainty would follow. However, countries may prefer to act simultaneously because of the larger uncertainties that are inherent in a sequential game.      

The tragedy of the commons revisited: The importance of group decision-making

We use a laboratory experiment to compare the way groups and individuals behave in an inter-temporal common pool dilemma. The experimental design distinguishes between a non-strategic problem where players (individuals or groups of three) make decisions without interaction and a strategic part where players harvest from a common pool. This allows us to correct for differences between individuals and groups in the quality of decisions when testing for differences in competitiveness. Group decisions are either made by majority rule or unanimity. The results show that groups are less myopic than individuals (i.e., they make qualitatively better decisions) but that they are more competitive than individuals when placed in a strategic setting. The net result for groups deciding by majority rule is that they make less efficient decisions in the strategic game than individuals do. We are able to show that this is caused by the median voter departing from her original preference in early periods with a shrinking pool. When groups have to make unanimous decisions they start playing the strategic game more efficiently then individuals do, but they rapidly become more competitive with repetition of the game.     

Letting third parties who suffer from petty corruption talk: Evidence from a collusive bribery experiment

Following a recommendation by Transparency International, we conduct a laboratory experiment to gauge the impact of a specific type of grassroots participation on petty corruption. Participants play a one-shot, three-person sequential bribery game that, depending on the treatment, either gives or does not give passive third parties suffering from corruption the opportunity to send a publicly visible message to potential bribers and bribees. We find that messaging opportunities deter bribe offers (i.e., the extensive margin of bribe), but affect neither the size of the offered bribe (i.e., the intensive margin) nor bribe acceptances. We conjecture that the different impact of the treatment on bribe-givers and bribe-takers may be due to the order of play.     

可持续公共债务水平下的政府违约问题研究

现实经济中存在公共债务具有可持续性时却发生政府违约的现象,本文在政府未来收支波动具有不确定性的假设下,建立一个政府与投资者的重复博弈模型以分析这一现象,研究发现:公共债务可持续性并不能完全排除政府违约风险,在政府未来基本盈余不确定的条件下,理性投资者愿意持有的公共债务水平远低于可持续的公共债务水平,两者的差异取决于政府对未来基本盈余的控制能力.     

The value of information in oligopoly with demand uncertainty

This paper discusses the value of information in supermodular and submodular games, using a simple duopoly model where the level of demand is uncertain. It is shown that the value of information issuperadditive (resp.,subadditive) between players if the game issupermodular (resp.,submodular). For example, in a Bertrand (resp., Cournot) market with (possibly imperfect) substitute products, one firm's information acquisition increases (resp., decreases) the other firm's incentive to acquire the same information. Furthermore, when the game is either supermodular or submodular, the value of information is higher when the player isexpected to be informed according to the opponent's belief than when the player is expected to be uninformed; this result is reversed when the game has asymmetric modularity (i.e., one player's action is substitutional to the other's, and the latter's action is complemental to the former's). These qualitative observations have a potential to be applied to a larger class of games with uncertainty where payoffs are smooth (e.g., twice continuously differentiable) in actions and states.     

Elections with platform and valence competition

We study a game in which candidates first choose platforms and then invest in costly valences (e.g., engage in campaign spending). The marginal return to valence depends on platform polarization—the closer platforms are, the more valence affects the election outcome. Consequently, candidates without policy preferences choose divergent platforms to soften valence competition. Moreover, exogenous increases in incentives for valence accumulation lead to both increased valence and increased polarization—the latter because candidates seek to avoid the costs of extra valence. As a result, the increase in valence is smaller than it would have been with exogenous platforms. Finally, the model highlights the overlooked substantive importance of common modeling assumptions. Changing the source of uncertainty in our model from noise around the median voter's ideal point to a shock to one candidate's valence (as is common in the literature) leads to complete platform convergence for all parameter values.     

The Financial Resource Curse*

In this paper, we present a model of the financial resource curse (i.e., episodes of abundant access to foreign capital coupled with weak productivity growth). We study a two‐sector (i.e., tradable and non‐tradable) small open economy. The tradable sector is the engine of growth, and productivity growth is increasing with the amount of labor employed by firms in the tradable sector. A period of large capital inflows, triggered by a fall in the interest rate, is associated with a consumption boom. While the increase in tradable consumption is financed through foreign borrowing, the increase in non‐tradable consumption requires a shift of productive resources toward the non‐tradable sector at the expenses of the tradable sector. The result is stagnant productivity growth. We show that capital controls can be welfare‐enhancing and can be used as a second‐best policy tool to mitigate the misallocation of resources during an episode of financial resource curse.     

Ambiguity and Public Good Provision in Large Societies

In this paper, we consider the effect of ambiguity on the private provision of public goods. Equilibrium is shown to exist and be unique. We examine how provision of the public good changes as the size of the population increases. We show that when there is uncertainty, there may be less free‐riding in large societies.     

The Political Economy of the (Weak) Enforcement of Indirect Taxes

The objective of this paper is to understand the determinants of the enforcement level of indirect taxation in a positive setting. We build a sequential game where individuals, who differ in their willingness to pay for a taxed good, vote over the enforcement level. Firms then compete à la Cournot and choose the fraction of sales taxes to evade. We assume in most of the paper that the tax rate is set exogenously. Voters face the following trade‐off: more enforcement not only increases tax collection but also increases the consumer price of the goods sold in an imperfectly competitive market. We obtain that the equilibrium enforcement level is the one most preferred by the individual with the median willingness to pay, that it is not affected by the structure of the market (number of firms) and the firms’ marginal cost, and that it decreases with the resource cost of evasion and with the tax rate. We also compare the enforcement level chosen by majority voting with the utilitarian level. In the last section, we endogenize the tax rate by assuming that individuals vote simultaneously over tax rate and enforcement level. We prove the existence of a Condorcet winner and show that it entails full enforcement (i.e., no tax evasion at equilibrium). The existence of markets with less than full enforcement then depends crucially on the fact that tax rates are not tailored to each market individually.     

Sustainability in Uncertain Economies

A stochastic growth model with a list of capital assets (i.e., reproducible capital, non-renewable resources, the knowledge base and institutions) is studied to evaluate the effects of different sources of uncertainty on sustainability. It is also discussed which measure can serve as an index of intergenerational welfare to evaluate sustainable development under uncertainty. The aim is to consider a more comprehensive setting than is usually explored in the literature and to generalize Arrow, Dasgupta and Mäler results to the case of uncertainty.     

The effect of ambiguity aversion on reward scheme choice

We test the implications of ambiguity aversion in a principal–agent problem with multiple agents. Models of ambiguity aversion suggest that, under ambiguity, comparative compensation schemes may become more attractive than independent wage contracts. We test this by presenting agents with a choice between comparative reward schemes and independent contracts, which are designed such that under uncertainty about output distributions (that is, under ambiguity), ambiguity averse agents should typically prefer comparative reward schemes, independent of their degree of risk aversion. We indeed find that the share of agents who choose the comparative scheme is higher under ambiguity.     

Corporate Social Responsibility in the work place

We analyze the effect of investments in corporate social responsibility (CSR) on workers’ motivation. In our experiment, a gift exchange game variant, CSR is captured by donating a certain share of a firm’s profit to charity. We are testing for CSR effects by varying the possible share of profits given to charity. Additionally, we investigate the effect of matching mission preferences, i.e., a worker preferring the same charity the firm donates to. Our results show that, on average, workers reciprocate investments in CSR with increased effort. Matching mission preferences also result in higher effort, independently of the extent of the CSR investment.     

On model ambiguity and money neutrality

We solve for the equilibrium of a stochastic neo-classical continuous time model without and with money under model ambiguity. We show that: (i) the correction for ambiguity stemming from the money supply is nil at equilibrium; (ii) money is neutral with respect to the stock market equilibrium (the equity risk premium); (iii) money is not neutral with respect to consumption and capital accumulation, and its effect may be quantitatively substantial; (iv) the preference for model robustness affects all the real economic variables as well as the expected inflation rate and the nominal interest rate.     

Intertemporal equilibria with Knightian uncertainty

We study a dynamic and infinite-dimensional model with incomplete multiple prior preferences. In interior efficient allocations, agents share a common risk-adjusted prior and subjective interest rate. Interior efficient allocations and equilibria coincide with those of economies with subjective expected utility and priors from the agents? multiple prior sets. A specific model with neither risk nor uncertainty at the aggregate level is considered. Risk is always fully insured. For small levels of ambiguity, there exists an equilibrium with inertia where agents also insure fully against Knightian uncertainty. When the level of ambiguity exceeds a critical threshold, full insurance no longer prevails and there exist equilibria with inertia where agents do not insure against uncertainty at all. We also show that equilibria with inertia are indeterminate.     

Ambiguity and perceived coordination in a global game

In a global game, larger ambiguity is shown to decrease the amount of coordination each player perceives. Consequently, small uncertainty tends to select the Pareto dominated equilibrium of the game without uncertainty. Implications for models of financial crises are drawn.