Are short‐term effects of pollution important for growth and optimal fiscal policy?

We study optimal fiscal policy in a stock‐flow model of the environment within an endogenous growth framework, where some pollutants have a lasting impact on environmental quality which is restored through abatement expenditure, while others dissipate and hence, have a short‐term effect on the environment. All pollutants, however, affect the productivity of a public good negatively. Given that short‐term pollution, although it dissipates, is irreversible in this sense, a government cannot ignore its negative effects since this type of pollution lowers the productivity of all inputs. We find that a larger negative effect of short‐term pollutants as well as a higher congestion effect of private capital leads to corrective fiscal policies with higher optimal income tax and abatement expenditure rates, which have favorable growth consequences. Interestingly, we find that the rate of short‐term pollution does not affect optimal fiscal policy while that of the long‐term pollution does.     

Technology Transfer and the South's Participation in an International Environmental Agreement*

We develop a North–South model of international trade and transboundary pollution to analyze the relationship between environmental technology transfer and the South's incentive to join an international environmental agreement (IEA). We find necessary and sufficient conditions under which technology transfer will increase the South's incentive to join the IEA. We also find necessary and sufficient conditions under which the South's participation in the IEA will increase the market incentive for technology transfer. Results have clear policy implications for (i) the sequence of technology transfer and the South's IEA membership, and (ii) the legitimacy of the South's subsidies for technology transfer.     

Pollution Abatement Investment When Environmental Regulation Is Uncertain

In a dynamic model of a risk-neutral competitive firm that can lower its pollution emissions per unit of output by building up abatement capital stock, we examine the effect of a higher pollution tax rate on abatement investment both under full certainty and when the timing or the size of the tax increase is uncertain. We show that a higher pollution tax encourages abatement investment if it does not exceed a certain threshold rate. However, akin to the Diamond-Mirrlees tax anomaly, it is possible that a higher pollution tax rate results in more pollution. The magnitude uncertainty discourages abatement investment, but at the time of the actual tax increase the abatement investment path may shift either upward or downward. On the other hand, when the timing is uncertain, the abatement investment path always jumps upward, thus suggesting that the effect of magnitude uncertainty on the optimal investment path may be more pronounced than that of timing uncertainty. Further, we show that the ad hoc practice of raising the discount rate to account for the uncertainty leads to underinvestment in abatement capital. We show how the size of this underinvestment bias varies with the future tax increase. Finally, we show that a credible threat to accelerate the tax increase can induce more abatement investment.     

A NOTE ON “A ONE‐SECTOR NEOCLASSICAL GROWTH MODEL WITH ENDOGENOUS RETIREMENT”: EXISTENCE OF MULTIPLE STEADY STATES*

This note extends Matsuyama's 0–1 endogenous retirement choice model to the framework with continuous endogenous retirement choice to study the consumption‐saving decision and capital accumulation in an overlapping generation model. The conditions for the existence of multiple steady states have been derived. In contrast to the 0 or 1 labour choice, the partial retirement may be a stable steady state under the continuous endogenous retirement choice in the second period. And this implies that partial retirement may be a stable optimal choice. Also, we find that the retirement choice depends on the initial capital stock when there are multiple steady states.     

Intertemporal Emission Permits Trading Under Uncertainty and Irreversibility

This paper analyzes the effect of emission permit banking on clean technology investment and abatement under conditions where the stringency of the future cap is uncertain. We examine the problem of heterogeneous firms minimizing the cost of intertemporal emission control in the presence of stochastic future pollution standards and emission permits that are tradable across firms and through time. A firm can invest in clean capital (an improved pollution abatement technology) to reduce its abatement cost. We consider two possibilities: that investment is reversible or irreversible. Uncertainty is captured within a two period model: only the current period cap is known. We show that if banking is positive and marginal abatement costs are sufficiently convex, there will be more abatement and investment in clean technology under uncertainty than there would be under certainty and no banking. These results are at odds with the common belief that uncertainty on future environmental policy is a barrier to investment in clean capital. Moreover, under uncertainty and irreversibility, we find that there are cases where banking enables firms to invest more in clean capital.     

The Impact of Foreign Aid Linked to Infrastructure and Pollution Abatement

This paper studies the macroeconomic effects of foreign aid taking into account environmental quality. We develop a dynamic equilibrium model in which public investments in both infrastructure and pollution abatement can be co‐financed using domestic resources and international aid. We consider untied aid, aid fully tied to either infrastructure or abatement and aid equally tied to both expenditures. We find that when the extent to which agents are affected by environmental problems is taken into account, then, regardless of the chances of substitution between factors, transfers linked to both infrastructure and pollution abatement may be the best welfare‐enhancing alternative.     

The effects of environmental taxes and quotas on the optimal timing of emission reductions under Choquet–Brownian uncertainty

The effects of two environmental policy options for the reduction of pollution emissions, i.e. taxes and non-tradable quotas, are analyzed. In contrast to the prior literature this work endogenously takes into account the level of emissions before and after the adoption of the new environmental policy. The level of emissions is determined by solving the firm's profit maximization problem under taxes and fixed quotas. We find that the optimal adoption threshold under taxes is always larger than the adoption threshold under fixed quota, even in a setting characterized by ecological uncertainty and ambiguity – in the form of Choquet–Brownian motions – on future costs and benefits over adopting environmental policies.     

Investment in Tourism Market: A Dynamic Model of Differentiated Oligopoly

We present a theoretical dynamic model in tourism economics, assuming that the market for tourism is an oligopoly with differentiated products. Destinations can invest in order to improve their stock of physical, natural or cultural resources. Tourism flows yield current revenues, but they are usually detrimental for the stock of resources. We find the solution of the dynamic model, and in particular we find the open-loop Nash equilibrium of the game among destinations, under alternative settings, depending on whether the degree of differentiation among destinations is exogenous or endogenous. In particular, under the latter case, an increase of the number of destinations leads to a higher degree of product differentiation in steady state.     

Precautionary Principle and Robustness for a Stock Pollutant with Multiplicative Risk

The interest shown by policy makers and economists in the precautionary principle indicates the importance of model uncertainty in global warming policy. I show that through robust control, policy makers can implement the precautionary principle to regulate a stock pollutant, and I analyze its effect on expected steady state pollution taxes, stocks and welfare. The paper is broadly comprised of a theoretical part and an application to global warming policy. I find that: (1) an increase in either uncertainty about the model or risk about abatement cost increases expected steady state pollution taxes; (2) a robust policy is preferred for any level of model uncertainty and this preference increases for either higher model uncertainty or higher multiplicative risk and (3) the effect on expected steady state pollution taxes and stock of introducing model uncertainty is relatively small for high levels of model uncertainty. These results advocate using robust policies for a stock pollutant in the presence of model uncertainty.      

Optimal Investment in Clean Production Capacity

For the mitigation of long-term pollution threats, one must consider that both the process of environmental degradation and the switchover to new and cleaner technologies are dynamic. We develop a model of a uniform good that can be produced by either a polluting technology or a clean one; the latter is more expensive and requires investment in capacity. We derive the socially optimal pollution stock accumulation and creation of nonpolluting production capacity, weighing the tradeoffs among consumption, investment and djustment costs, and environmental damages. We consider the effects of changes in the pollution decay rate, the capacity depreciation rate, and the initial state of the environment on both the steady state and the transition period. The optimal transition path looks quite different with a clean or dirty initial environment. With the former, investment is slow and the price of pollution may overshoot the long-run optimum before converging. With the latter, capacity may overshoot.     

Longevity,Fertility and Economic Growth: Do Environmental Factors Matter?

Our study examines the effect of environmental factors on the economic decisions regarding fertility. We incorporate health‐damaging pollution into a three period overlapping generations model in which life expectancy, fertility and economic growth are all endogenous. We show that environmental factors can cause significant changes to the economy's demographics. In particular, the entrepreneurial choice of less polluting production processes, induced by a tax on emissions, can at some point in time lead to such changes as higher longevity and lower fertility rates. Thus, we provide a novel explanation on the positive relation between fertility rates and pollution. According to this, the causality on this relation may also work from the latter to the former. Furthermore, our model can account for the empirically observed N‐shaped correlation between pollution and income per capita.     

Portfolio Choice and Liquidity Constraints*

We study the infinite‐horizon model of household portfolio choice under liquidity constraints and revisit the portfolio specialization puzzle. We show why the puzzle is robust to several model variations, and argue that positive correlation between earnings shocks and stock returns is unlikely to provide an empirically plausible resolution. We find that relatively small fixed costs for stock market entry are sufficient to deter stockholding because, for a plausible range of parameter values, households can achieve desired consumption smoothing with small or zero holdings of stocks. Such costs could arise from informational considerations, sign‐up fees, and investor inertia.     

Taxation of a Polluting Non-renewable Resource in the Heterogeneous World

This paper extends the literature on the taxation of polluting exhaustible resources by taking international heterogeneities and national tax-setting into account. We propose a two-country Romer model of endogenous growth in which the South is endowed with the stock of an essential polluting non-renewable resource and world economic growth is driven by a northern research sector. We consider the stock of pollution as affecting global welfare. First, we characterize the optimal environmental taxation policies. Second, we examine the impacts of national taxes. Their time profile determines the extraction path, the dynamics of pollution accumulation and that of world output. Their respective levels entail inter-country interactions by altering the efficiency of the world resource allocation, the tax revenues and the resource rents. We study isolatedly the distortional and distributional effects of local taxes. Then, we completely assess the overall impact of a unilateral tax increase. Finally, we find that, even if heterogeneous countries coordinate their taxation policies to correct the global environmental problem, their divergent strategic interests cause another global, non-environmental distortion in the allocation of the resource.     

Trade and Global Pollution in Dynamic Oligopoly with Corporate Environmentalism

This paper examines the effects of international trade in the presence of dynamic oligopolistic competition where the stock of global pollution has a negative welfare effect and the oligopolists' objectives may include society's pollution damage as well as private profits. In a symmetric case where the number of firms, emission coefficient, and firms' environmental consciousness are the same in two countries, an opening of trade unambiguously improves each country's welfare in the short run. In the long run, however, trade increases the stock of global pollution and hence, whether opening of trade is beneficial depends on the parameters of the economy. If there are asymmetries between countries, the short‐run gains from trade in both countries are not necessarily guaranteed, because trade liberalization may increase output in one country and reduce it in the other. Moreover, free trade may result in lower pollution stock than under autarky.     

Pollution Control in Open Economies: Implications of Within-period Interactions for Dynamic Game Equilibrium

This paper examines a two-country, dynamic game model of pollution control in the presence of economic interactions between countries within a period, as well as the environmental interaction between periods (i.e., a change in the stock of global pollution). These economic interactions emerge because of changes in the terms of trade of polluting goods or the market share of domestic polluting industries. It is shown that if within-period externalities exist, a noncooperative equilibrium may result in a smaller stock of global pollution in the steady state than does international cooperation. Moreover, the properties of equilibrium paths depend on the direction and size of such externalities. In addition, trigger strategy equilibria that achieve the outcome of the collusive solution are examined.     

Can Rich Countries Become Pollution Havens?*

This paper bridges the gap between two‐country Ricardian trade models where differences in environmental policies create pollution havens in a poorer region with weaker pollution regulations, and 2 × 2 Heckscher–Ohlin models that predict under certain conditions that pollution havens may occur in a richer region with tighter regulations. By relaxing the Heckscher–Ohlin assumptions of factor price equalization and no specialization, we show how creation of pollution havens in either region is possible, due to the interplay of policy and factor‐endowment motives. We also analyze the conditions for creating pollution havens in the cases of exogenous and endogenous environmental policy.     

Birth,death and public good provision

We explore the effect of fixed versus dynamic group membership on public good provision. In a novel experimental design, we modify the traditional voluntary contribution mechanism (VCM) by periodically replacing old members of a group with new members over time. Under this dynamic, overlapping generations matching protocol we find that average contributions experience significantly less decay over time relative to a traditional VCM environment with fixed group membership and a common termination date. These findings suggest that the traditional pattern of contribution and decay seen in many public goods experiments may not accurately reflect behavior in groups with changing membership, as is the case in many real-world environments.     

Prices versus quantities versus bankable quantities

Quantity-based regulation with banking allows regulated firms to shift obligations across time in response to periods of unexpectedly high or low marginal costs. Despite its wide prevalence in existing and proposed emission trading programs, banking has received limited attention in past welfare analyses of policy choice under uncertainty. We address this gap with a model of banking behavior that captures two key constraints: uncertainty about the future from the firm's perspective and a limit on negative bank values (e.g. borrowing). We show conditions where banking provisions reduce price volatility and lower expected costs compared to quantity policies without banking. For plausible parameter values related to U.S. climate change policy, we find that bankable quantities produce behavior quite similar to price policies for about two decades and, during this period, improve welfare by about a $1 billion per year over fixed quantities.     

SHORT-TERM CONTRACTS REGULATIONS AND DYNAMIC LABOUR DEMAND: THEORY AND EVIDENCE

We present a dynamic labour demand model where we evaluate the impact of employment regulations on permanent and temporary employment. We consider three different kinds of regulations, namely firing costs, hiring costs and a constraint on temporary contracts. These regulations differently affect the size and composition of employment. The theoretical results are interpreted and questioned on the basis of empirical evidence on the employment effects of the regulation reforms that occurred in the major European countries in the period 1983–1999. The empirical analysis is based on a new set of time‐varying indicators on permanent employment protection, fixed‐term contracts and temporary agency work regulations. We find evidence in support of the hypothesis that fixed‐term contracts have been effective stepping‐stones to permanent jobs during the period under observation. On the contrary, flexible temporary agency work regulations seem to induce a substitution of permanent with temporary contracts.     

Uncertainty and Consumer Durables Adjustment

We characterize infrequent durables stock adjustment by consumers who also derive utility from non-durable consumption flows in the presence of idiosyncratic income uncertainty. The data we analyse include subjective future income uncertainty measures, which we use as instruments in the estimation of relevant parameters of heterogeneous consumers' dynamic adjustment problems. The data feature two conceptually distinct sources of variation: cross-sectional heterogeneity of the sampled households' dynamic problems, and history-dependent heterogeneity in their situation during the observation period. We note that the latter should affect the likelihood but not the size of stock adjustment decisions, and find broad support for theoretical predictions in formal selection-controlled regressions based on this insight.