The effect of climate change on optimal wetlands and waterfowl management in Western Canada

Warmer temperatures and a decrease in precipitation in the 21st century could severely deplete wetlands in the prairie pothole region of western Canada. In this study, we employ linear regression analysis to determine the casual effect of climate change on wetlands in this region, with temperature, precipitation and the standardized precipitation index (SPI) used to predict the effect of potential climate change on wetlands. We then use a waterfowl-wetlands bioeconomic model to solve for socially optimal levels of duck harvests and wetlands retention under current climate conditions and various climate change scenarios. The model maximizes benefits to hunters plus the amenity values of ducks to non hunters and the non-market ecosystem benefits of wetlands. Results indicate that climate change could decrease wetlands by between 7 and 47%, and that the optimal number of wetlands to retain could decrease by as much as 38% from the baseline climate.     

Differences and similarities between ecological and economic models for biodiversity conservation

In this paper we investigate an important obstacle which substantially complicates co-operation between ecologists and economists but which has received little attention so far: differences between the modelling approaches in economics and ecology. To understand these differences, 60 models addressing issues relevant to biodiversity conservation have been selected randomly from eight international economic and ecological journals. The models have been compared according to a number of criteria including the models' level of generality; the mathematical techniques employed for formulation and solution of the models; the level of complexity and the way time, space and uncertainty are taken into account. The economic models sampled are formulated and analysed analytically, tend to be relatively simple and are mostly used to investigate general questions. Furthermore, they often ignore space, dynamics and uncertainty. Although some ecological models have similar properties, there is also a substantial number of another type of ecological models that are relatively complex and analysed by simulation. These models tend to be rather specific and often explicitly consider dynamics, space and uncertainty. The integrated ecological-economic models are observed to lie “in the middle” between ecological and economic models. An unexpected result is that they are not more complex than ecological and economic models (as one could have expected from a simple “merger” of models from both disciplines), but have an intermediate complexity.     

The ghost of extinction: Preservation values and minimum viable population in wildlife models

The inclusion of a minimum viable population in bioeconomic modeling creates at least two complications that are not resolved by using a modified logistic growth function. The first complication can be dealt with by choosing a different depensational growth function. The second complication relates to the inclusion of the in situ benefits of wildlife into the analysis. Knowledge about the magnitude of the in situ benefits provides no guide for policy about conservation management. Simply knowing that people are willing to pay a large amount each year to protect a species says nothing about whether one should manage habitat to protect or enhance the species' numbers, unless the species is in imminent danger of extinction. If willingness to pay is to be a guide, it needs to be better tied to population numbers, especially the minimum viable population.     

Modeling nonlinear Granger causality between the oil price and U.S. dollar: A wavelet based approach

In this paper, we use a wavelet approach to study the linear and nonlinear Granger causality between the real oil price and the real effective U.S. Dollar exchange rate. Instead of analyzing the time series at their original level, as it is usually done, we first decompose the two macroeconomic variables at various scales of resolution using wavelet decomposition and then we study the relationships among the decomposed series on a scale by scale basis. A major finding of this paper is that the linear and nonlinear causal relationships between the real oil price and the real effective U.S. Dollar exchange rate vary over frequency bands as it depends on the time scales. Indeed, there is a strong bidirectional causal relationship between the real oil price and the real dollar exchange rate for large time horizons, i.e. corresponding to fundamentalist traders, especially fund managers and institutional investors. But, for the first frequency band which corresponds to a class of traders whom investment horizon is about 3-months and whom trading is principally speculative (noise traders), the causality runs only from the real oil prices to real effective U.S dollar exchange rate.     

Tangency capacity notions based upon the profit and cost functions: A non-parametric approach and a general comparison

This contribution provides a way to define and compute a tangency notion of economic capacity based upon the relation between the various directional distance functions and the profit and cost functions using non-parametric technologies. A new result relating profit and cost function-based tangency capacity notions is established.     

Anticipation effects of technological progress on capital accumulation: a vintage capital approach

Due to embodied technological progress new generations of capital goods are more productive. Therefore, in order to study the effects of technological progress, a model must be analyzed in which different generations of capital goods can be distinguished. We determine in what way the firm adjusts current investments to predictions of technological progress. In the presence of market power we show that a negative anticipation effect occurs, i.e. current investments in recent generations of capital goods decline when faster technological progress will take place in the future, because then it becomes more attractive to wait for new generations of capital goods. In case that only investments in new machines are possible, actually a whole wave of anticipation phases arises.     

A structural dynamic microsimulation model of household savings and labour supply

A structural model of the household is described that represents current best-practice in the analysis of savings and labour supply responses to the policy environment. Care has been taken in specifying the model so that it represents an appropriate basis for the analysis of incentive effects to policy change, and for exploring the empirical support for alternative structural assumptions. Matching the model to survey data for the UK reveals some interesting puzzles in relation to the timing of retirement.     

A critical review of multi-criteria decision making methods with special reference to forest management and planning

This paper provides a review of research contributions on forest management and planning using multi-criteria decision making (MCDM) based on an exhaustive literature survey. The review primarily focuses on the application aspects highlighting theoretical underpinnings and controversies. It also examines the nature of the problems addressed and incorporation of risk into forest management and planning decision making. The MCDM techniques covered in this review belong to several schools of thought. For each technique, a variety of empirical applications including recent studies has been reviewed. More than 60 individual studies were reviewed and classified by the method used, country of origin, number and type of criteria and options evaluated. The review serves as a guide to those interested in how to use a particular MCDM approach. Based on the review, some recent trends and future research directions are also highlighted.     

The effects of tariffs on coalition formation in a dynamic global warming game

The prospects for cooperation on climate protection beyond 2012 are currently uncertain. Thus policy instruments which foster participation in International Environmental Agreements (IEA) are in demand. Among the instruments under discussion are trade sanctions. Multi-region optimal growth models are a state of the art tool for integrated assessment, but introducing trade sanctions distorts the competitive equilibrium, making it difficult to compute numerically. We introduce trade and trade sanctions into a model of coalition stability to assess the potential of trade sanctions to support an IEA. Trade is modeled by having all countries produce a generic output good, but adopting national product differentiation (Armington assumption). Coalitions are free to impose tariffs on imports from non-cooperating countries. We solve the model numerically using a refined version of Negishi's [Negishi, T., 1960. Welfare economics and existence of an equilibrium for a competitive economy. Metroeconomica 12, 92–97] basic algorithm. We then apply the model to analyze the influence of tariffs on international cooperation. The model suggests that there is indeed a significant potential to raise participation through trade sanctions, even when goods from different countries are nearly perfect substitutes. Furthermore we investigate the effect of trade sanctions on global welfare, environmental effectiveness, and the credibility of the tariff mechanism.     

Double dividend,dynamic Laffer effects and public abatement

In a very stylized endogenous growth economy with pollution and public abatement activities and without any production externality, we show that the government may exploit dynamic Laffer effects to achieve a double dividend through an environmental tax reform, while fulfilling its commitment to provide an exogenously specified sequence of expenditures in the form of lump-sum transfers to consumers.     

Modelling the world wool market: A hybrid approach

We present a model of the world wool market that merges two modelling traditions: the partial-equilibrium commodity-specific approach and the computable-general-equilibrium approach. The model captures the multistage nature of the wool production system, and the heterogeneous nature of raw wool, processed wool and wool garments. It also captures the important wool producing and consuming regions of the world. We illustrate the utility of the model by estimating the effects of tariff barriers on wool products using partial- and general-equilibrium solutions. We find that either solution generates similar wool industry results, whereas the macroeconomic effects differ significantly with the partial-equilibrium estimates significantly overestimating the benefits of the tariff changes.     

Cooperation and framing effects in provision point mechanisms: Experimental evidence

Andreoni (1995) showed that pure framing effects may influence contribution in Voluntary Contribution Mechanisms (VCM) by comparing a standard public goods game, called the positive frame condition (giving to the public good), with a negative frame condition (taking from the public good) where the subjects' choice to purchase a private good makes the other subjects worse off. This paper aims at testing the robustness of such framing effects in the context of Provision Point Mechanisms (PPM). Our approach is original in that it combines both framing and provision point dimensions by comparing maintaining (taking from the public good) and creating (giving to the public good) contexts using Provision Point experiments. Consistent with previous findings, we find that individuals tend to be less cooperative in the maintaining frame than in the creating frame. Our results also show that the framing effects are stronger under a PPM than under a VCM and increase with the provision point level. These results may have important consequences for the management of environmental resources.     

Measuring stress in money markets: A dynamic factor approach

We extract an index of interest rate spreads from various money market segments to assess the level of funding stress in real time. We find that during the 2007–2009 financial crisis, money markets switched between low and high stress regimes except for brief periods of extreme stress. Transitions to lower stress regimes are typically associated with the non-standard policy measures by the Federal Reserve.     

Measuring and Optimizing Portfolio Credit Risk: A Copula‐based Approach*

In this work, we present a methodology for measuring and optimizing the credit risk of a loan portfolio taking into account the non‐normality of the credit loss distribution. In particular, we aim at modelling accurately joint default events for credit assets. In order to achieve this goal, we build the loss distribution of the loan portfolio by Monte Carlo simulation. The times until default of each obligor in portfolio are simulated following a copula‐based approach. In particular, we study four different types of dependence structure for the credit assets in portfolio: the Gaussian copula, the Student's t‐copula, the grouped t‐copula and the Clayton n‐copula (or Cook–Johnson copula). Our aim is to assess the impact of each type of copula on the value of different portfolio risk measures, such as expected loss, maximum loss, credit value at risk and expected shortfall. In addition, we want to verify whether and how the optimal portfolio composition may change utilizing various types of copula for describing the default dependence structure. In order to optimize portfolio credit risk, we minimize the conditional value at risk, a risk measure both relevant and tractable, by solving a simple linear programming problem subject to the traditional constraints of balance, portfolio expected return and trading. The outcomes, in terms of optimal portfolio compositions, obtained assuming different default dependence structures are compared with each other. The solution of the risk minimization problem may suggest us how to restructure the inefficient loan portfolios in order to obtain their best risk/return profile. In the absence of a developed secondary market for loans, we may follow the investment strategies indicated by the solution vector by utilizing credit default swaps.     

Groundwater balance and conservation under different water pricing and agricultural policy scenarios: A case study of the Hamadan-Bahar plain

Government subsidies for agricultural activities in recent decades have encouraged farmers of Hamadan-Bahar plain to extend the number of wells and irrigated farms, with no consideration of groundwater resource conservation. As a result, the level of the groundwater table has decreased continuously in this area, threatening the life of groundwater aquifer. The objective of the study is to analyze the impacts of irrigation water pricing and agricultural policy scenarios on aquifer conservation by considering the dynamic relations between aquifer groundwater balance and the agriculture sector. For this purpose a combination of simulation and optimization techniques is considered in a dynamic framework. Firstly, dynamic treatments of groundwater and the main factors affecting the balance of studied aquifer are simulated. Then, optimization behaviour of agriculture sector related to farmers' decision-making processes is defined on the time horizon. Thereafter all of the equations are used simultaneously by a non-linear dynamic programming method, which maximize present value of gross margins of agriculture sector subject to groundwater constrains and other input limitations. The analysis of the results indicates that water pricing by itself can considerably reduce the agricultural demand for aquifer groundwater in the Hamadan-Bahar plain.     

Uncertain spatial demand and price flexibility: A state space approach to duopoly

Sufficient conditions for a unique price equilibrium, in terms of the uncertainty distribution and the state contingent consumer distributions, are given for spatial duopoly. Also considered are efficiency and endogenous locations for the symmetric case and comparative statics on price flexibility.     

Military expenditure and economic growth across different groups: A dynamic panel Granger-causality approach

Applying GMM (Arellano and Bond, 1991) to panel data of 90 countries spanning over 1992–2006, this paper explores possible relationships between military expenditure and economic growth. Based on the definitions of income levels by the World Bank – high, middle and low – our results indicate military spending leads negatively economic growth for the panels of low income countries with a marginally significance level of 10%. Of four different regional panels (Africa, Europe, the Middle East–South Asia and Pacific Rim), a negative but stronger (5% significance level) causal relationship from military expenditure to economic growth is found for the Europe and Middle East–South Asia regions.     

Pricing the ecosystem and taxing ecosystem services: A general equilibrium approach

In an integrated dynamic general equilibrium model of the economy and the ecosystem humans and other species compete for land and prey biomass. Each submodel exhibits a price-driven competitive allocation mechanism, and the endogenously determined habitat is either openly accessible or privately owned. In both scenarios specific corrective taxes or subsidies are needed to internalize ecosystem externalities. An open access habitat causes additional inefficiencies through diverging prices for biomass and land in both subsystems. Values of all ecosystem components are determined in an efficient steady state clarifying the role and the interplay of ecosystem prices and economic prices.     

Stunting and selection effects of famine: A case study of the Great Chinese Famine

Many developing countries experience famine. If survival is related to height, the increasingly common practice of using height as a measure of well-being may be misleading. We devise a novel method for disentangling the stunting from the selection effects of famine. Using data from the 1959-1961 Great Chinese Famine, we find that taller children were more likely to survive the famine. Controlling for selection, we estimate that children under the age of five who survived the famine grew up to be 1 to 2 cm shorter. Our results suggest that if a country experiences a shock such as famine, average height is potentially a biased measure of economic conditions during childhood.