Uncertainty,Learning and International Environmental Policy Coordination

In this paper we construct a simple model of global warming which captures a number of key features of the global warming problem: (i) environmental damages are related to the stock of greenhouse gases in the atmosphere; (ii) the global commons nature of the problem means that these are strategic interactions between the emissions policies of the governments of individual nation states; (iii) there is uncertainty about the extent of the future damages that will be incurred by each country from any given level of concentration of greenhouse gases but there is the possibility that at a future date better information about the true extent of environmental damages may become available; an important aspect of the problem is the extent to which damages in different countries may be correlated. In the first part of the paper we consider a simple model with two symmetric countries and show that the value of perfect information is an increasing function of the correlation between damages in the two countries in both the cooperative and non-cooperative equilibria. However, while the value of perfect information is always non-negative in the cooperative equilibrium, in the non-cooperative equilibrium there is a critical value of the correlation coefficient below which the value of perfect information will be negative. In the second part of the paper we construct an empirical model of global warming distinguishing between OECD and non-OECD countries and show that in the non-cooperative equilibrium the value of perfect information for OECD countries is negative when the correlation coefficient between environmental damages for OECD and non-OECD countries is negative. The implications of these results for international agreements are discussed.     

What explains the value premium? The case of adjustment costs,operating leverage and financial leverage

This paper empirically examines and compares the different theoretical predictions on how adjustment costs, operating and financial leverage influence the value premium. Consistent with Ozdagli (2012), financial leverage plays a dominant role, supported by adjustment costs (which represent the degree of investment irreversibility). Specifically, the observed value premium is driven by the financial leverage differences between value and growth firms, partially neutralized by investment irreversibility. The relation between the value premium and investment irreversibility is contrary to the intuition in Zhang (2005) and Cooper (2006). Operating leverage does not significantly influence the value premium.     

Energy Prices and Carbon Taxes under Uncertainty about Global Warming

This paper extends the strategic interactions between producers of fossil fuels concerned about their profits and a taxing government concerned about the consumers’ welfare for uncertainty: global warming follows an Itô -process. Stochasticity requires to differentiate between reversible and irreversible emissions in contrast to the deterministic version. The unconstrained (= reversible) case allows for a closed form solution but not the more realistic and constrained case. Nevertheless interesting analytical properties (e.g. about when to stop emissions, implicit conservation due to monopolistic supply) are derived and complemented by a numerical example.     

Evaluating Projects and Assessing Sustainable Development in Imperfect Economies

We are interested in three related questions:(1) How should accounting prices be estimated?(2) How should we evaluate policy change in animperfect economy? (3) How can we check whetherintergenerational well-being will be sustainedalong a projected economic programme? We do notpresume that the economy is convex, nor do weassume that the government optimizes on behalfof its citizens. We show that the same set ofaccounting prices should be used both forpolicy evaluation and for assessing whether ornot intergenerational welfare along a giveneconomic path will be sustained. We also showthat a comprehensive measure of wealth,computed in terms of the accounting prices, canbe used as an index for problems (2) and (3)above. The remainder of the paper is concernedwith rules for estimating the accounting pricesof several specific environmental naturalresources, transacted in a few well knowneconomic institutions.     

Joint Management of Emission Abatement and Technological Innovation for Stock Externalities

We investigate how emission abatement and technological innovation provide different solutions to reduce pollutant emissions. In the case of a stock externality emission abatement leads to a smooth and continuous adjustment of emissions. Conversely, technological innovation has to be interpreted as an option on a less polluted environment and can justify the use of a pollution threshold above which it is optimal to start a research and development programme for a less polluting technology. It is shown that technological innovation interferes with the traditional emission abatement approach. The optimal abatement level is logically lowered once the less polluting technology is available; nevertheless a temporary increase in emissions is optimal during the research and development period. The usual Pigouvian tax system proves to remain an efficient corrective instrument. A numerical application to the Greenhouse effect is provided.     

Econometric modelling in the presence of evolutionary change

A methodology is offered which can be used to construct an econometricmodel in the presence of structural change of an evolutionarytype. The theoretical basis for such modelling is drawn fromthe self-organisation approach and operationalised in the contextof the logistic diffusion growth model. The latter is augmentedto allow for the impact of exogenous effects upon both the diffusionrate and boundary limit. We show how the hypothesis of augmentedlogistic diffusion can be falsified using econometric methods.An illustrative case study is used, namely the growth and declineof Australian Building Society Deposits. With the aid of thisexample, it is shown how the approach could be of use to botheconomic forecasters and regulators in conditions of structuralchange where conventional econometric methods are often inappropriate.     

Uncertain Climate Change in an Intergenerational Planning Model

A three-generation planning model incorporating uncertain climate change is developed. Each generation features a production activity based on capital and an exhaustible resource. An irreversible climate change may occur in period two or three, reducing the productivity for this and the remaining generation. The model is solved by stochastic dynamic programming. If the climate impact and climate change probability is constant, the optimal period one (and two) resource extraction is larger than for the reference case of climate stability. If, however, climate impact and climate change probability increases with increased aggregate resource use, this result is reversed.     

Uncertainty and the Cost of Reversal

For standard irreversibility theory the prospect of acquiring better information in the future should induce more flexible decisions: the “irreversibility effect”. This result relies on the definition of an irreversible position as one that would be technically or economically impossible to reverse. In practice, many positions can be reversed at an affordable cost. In this case an increase in informativeness alone is not enough to bias decisions in favour of more flexibility. We look for restrictions on decision sets, information structures and preferences that make possible to study the effect of information on flexibility. JEL Classification No: D81, D9     

Investment, uncertainty and irreversibility

This paper investigates the irreversibility of investments and the impact this has on the nature of the relationship between investment and uncertainty. The empirical analysis uses firm‐level data and is based on a survey of 210 rice‐milling firms in the Mekong River Delta in Vietnam, which was carried out during the year 2000. We show that uncertainty reduces investment of rice millers in the presence of irreversibility, as is predicted by the real options approach to investment. We do not find evidence that the negative association between uncertainty and investment is influenced by the degree of irreversibility.     

Valuation and management of tropical forests

This paper develops a framework for the valuation and management of tropical forests that reflects their ecological and economic characteristics. The analysis demonstrates the importance of modeling the feasible use patterns and the information structure in tropical forest management decisions. The model predicts that cases exist where the foresighted management of forests leads to more preservation than the traditional expected value approach. An application in Thailand provides evidence that such cases occur in relevant ranges of benefit flows. The model focuses tropical forest management on assessments of sustainability and feasible sequences in light of uncertainty and information flows.