Mountain-to-sea ecological-resource management: Forested watersheds,coastal aquifers,and groundwater dependent ecosystems

Improving the understanding of connections spanning from mountain to sea and integrating those connections into decision models have been increasingly recognized as key to effective coastal resource management. In this paper, we aim to improve our understanding of the relative importance of linkages between a forested watershed, a coastal groundwater aquifer, and a nearshore marine groundwater-dependent ecosystem (GDE) using a dynamic groundwater optimization framework and simple ecosystem equations. Data from the Kīholo aquifer on the Kona Coast of Hawai‘i Island are used to numerically illustrate optimal joint management strategies and test the sensitivity of those strategies to variations in physical and behavioral parameter values. We find that for a plausible range of watershed management costs, protecting part of the recharge capture area is always optimal. Without watershed protection, maintaining a safe minimum standard growth rate for a GDE-dependent marine indicator species, reduces net present value non-trivially, but optimal investment in watershed conservation offsets that potential reduction by 75 %. In general, we find that optimal watershed management and groundwater pumping are most sensitive to changes in water demand growth and parameters that describe nearshore salinity.     

Maritime trade and migratory species management to protect biodiversity

Invasive species threaten biodiversity worldwide. Ships inadvertently carry marine invasive species to vulnerable ports. An empirical game theoretic analysis is presented to explore this transboundary biological pollution topic. This analysis utilizes data on marine invasive species and maritime trade as a vector of impact on native species at different public port locations along the Pacific coast of the North American countries. Preventative and reactive abatement strategies are compared. The countries are not identical and a comparison of noncooperative game strategies and payoffs to the cooperative game is presented. With the asymmetry between countries, optimal sharing rules are quantified. Results show that cooperative and preventative abatement is optimal compared to all other strategies dealing with stock and flow pollution.      

Groundwater management under heterogeneous land tenure arrangements

We develop a groundwater extraction model that considers the Marshallian inefficiency associated with sharecropping and use data from Pakistan to simulate the impact of an open access regime and of optimal management on groundwater extractions, the state of the aquifer, and annual net benefits through time. We also evaluate a price instrument as a mechanism of inducing optimal extractions. Under both open access and optimal management, we observe notable differences in groundwater extractions and the water table level between the tenure model (which considers the behavior of both owner cultivators and sharecroppers) and the baseline model (which includes the behavior of only owner cultivators). We also find a modest difference in the aggregate net benefits generated by the two models. The results offer new insights—vis-à-vis land tenure heterogeneity—into the evaluation of more effective policies for groundwater management and aquifer sustainability.     

Assimilation of Time Series Data into a Dynamic Bioeconomic Fisheries Model: An Application to the North East Arctic Cod Stock

This paper combines the elegant technique of Data Assimilation and a Monte Carlo procedure to analyze time series data for the North East Arctic Cod stock (NEACs). A simple nonlinear dynamic resource model is calibrated to time series data using the variational adjoint parameter estimation method and the Monte Carlo technique. By exploring the efficient features of the variational adjoint technique coupled with the Monte Carlo method, optimal or best parameter estimates with their error statistics are obtained. Thereafter, the weak constraint formulation resulting in a stochastic ordinary differential equation (SODE) is used to find an improved estimate of the dynamical variable, i.e. the stock. Empirical results show that the average fishing mortality imposed on the NEACs is about 16% more than the intrinsic growth rate of the biological species.     

Economics of biodiversity and sustainable fisheries management

Marine ecosystems are complex, and many marine species are ecologically interdependent. As a result, losing a species could produce a cascading effect on other species. Fishery scientists advocate an ecosystem-based approach to fishery management to meet long-term sustainable goals. This paper models the complex interrelationships among species and the relationship between biomass growth and phenotypic diversity. We found that the equilibrium stock and catch/yield levels are overestimated when the diversity is not accounted for. Consequently, if species are diverse, fishery policy based on a single fishery management could overestimate catch potentials and potentially results in biological overfishing and stock collapse.     

Optimal Extraction of a Polluting Nonrenewable Resource with R&D toward a Clean Backstop Technology

We study the optimal extraction of a polluting nonrenewable resource within the following framework: environmental regulation is imposed in the form of a ceiling on the stock of pollution and a clean unlimited backstop technology can be developed by research and development. More specifically, the time taken to develop a new technology depends on the amount spent on R&D. A surprising result is that the stringency of the ceiling and the size of the initial stock of the polluting nonrenewable resource have a bearing on whether environmental regulation speeds up the optimal arrival date of this new technology. Compared to a scenario with no environmental externalities, stringent environmental regulation drives up the optimal R&D investment and brings forward the optimal backstop arrival date only in the case of a large initial resource stock. Otherwise, if the initial resource stock is small, regulation reduces optimal R&D and postpones the optimal backstop arrival date. These results are explained by the two roles played by the backstop technology. First, the backstop serves to replace oil once it has been exhausted. As extraction is slowed down by regulation, the exhaustion of the nonrenewable resource is postponed and the long‐run gains of innovation are lowered. Second, environmental regulation raises the short‐run gains of innovation by increasing the cost of consuming just oil.     

Effects of instantaneous groundwater availability on irrigated agriculture and implications for aquifer management

Groundwater is an important input for agricultural production in many parts of the world. Aquifer depletion has been shown to affect the rate that groundwater can be extracted from an aquifer. In this paper, we develop an analytical framework that accounts explicitly for the effects of limited instantaneous groundwater extraction rate (well capacity) on a producer's irrigation decisions. We show that limited well capacities can affect the producer’s groundwater use and profit. We draw three important insights from these findings. First, we demonstrate that the price elasticity of demand for groundwater is higher for lower well capacities. Second, farmers’ irrigation decisions are non-monotonic with respect to well capacity and climate conditions. Under a drier climate, producers with greater well capacities increase their groundwater use, and producers with lower well capacities reduce their water use. Third, through numerical analysis, we show that considering spatial heterogeneity in well capacities is important for estimating the cost-effectiveness and distributional impacts of groundwater management policies. Our results shed new light on the importance of extraction capacity for groundwater management policies and the potential impacts of climate change on agricultural production.     

Testing the Assumptions and Predictions of the Hotelling Model

In this paper, we empirically examine whether the assumptions and predictions of the Hotelling model are consistent with patterns observed in data. We consider nonlinear functional forms for the extraction cost and resource demand to develop an empirical Hotelling model with technological progress and stock dependent extraction costs. Using panel data on fourteen nonrenewable natural resources to estimate this empirical Hotelling model, we get qualitatively different results as compared to the related literature. We find evidence of stock-dependent extraction costs for most resources. There is no evidence against the linearity of the optimal extraction rate in the resource stock for almost all resources studied. Furthermore, the Hotelling model may sustain a zero long-run growth rate in resource prices. These results depend on whether firms use different extractive technologies or whether the structural break observed on resource prices is taken into account.     

Joint Quantity/Quality Management of Groundwater

Economic literature on groundwater managementhas traditionally been split into two areas: there are papers that evaluate different schemes of dynamicaquifer management, considering that pumping costs vary with stock but ignoring water quality. On the other hand, there are papers that considercontamination problems caused by specificpollutants. This paper presents two alternative models for joint quantity-quality management, and it shows that existing models are in fact special cases of these. The framework isdynamic and considers both the stock of waterquantity and a stock measure of water quality. Optimal taxes are derived, and shown to be different from those in existing quantity-only or quality-only models. Implementationproblems are briefly discussed.     

Optimal Mechanisms for Heterogeneous Multi-Cell Aquifers

Standard economic models of groundwater management impose restrictive assumptions regarding perfect transmissivity (i.e., the aquifer behaves as a bathtub), no external effects of groundwater stocks, observability of individual extraction rates, and/or homogeneous agents. In this article, we derive regulatory mechanisms for inducing the socially optimal extraction path in Markov perfect equilibrium for aquifers in which these assumptions do not hold. In spite of the complexity of the underlying system, we identify an interesting case in which a simple linear mechanism achieves the social optimum. To illustrate potential problems that can arise by erroneously imposing simplifying assumptions, we conduct a simulation based on data from the Indian state of Andhra Pradesh.     

A dynamic approach to PES pricing and finance for interlinked ecosystem services: Watershed conservation and groundwater management

A theory of payment for ecosystem services (PES) pricing consistent with dynamic efficiency and sustainable income requires optimized shadow prices. Since ecosystem services are generally interdependent, this requires joint optimization across multiple resource stocks. We develop such a theory in the context of watershed conservation and groundwater extraction. The optimal program can be implemented with a decentralized system of ecosystem payments to private watershed landowners, financed by efficiency prices of groundwater set by a public utility. The theory is extended to cases where land is publicly owned, conservation instruments exhibit non-convexities on private land, or the size of a conservation project is exogenous. In these cases, conservation investment can be financed from benefit taxation of groundwater consumers. While volumetric conservation surcharges induce inefficient water use, a dynamic lump-sum tax finances investment without distorting incentives. Since the optimal level of conservation is generated as long as payments are correct at the margin, any surplus can be returned to consumers through appropriate block pricing. The present value gain in consumer surplus generated by the conservation-induced reduction in groundwater scarcity serves as a lower bound to the benefits of conservation without explicit measurement of other benefits such as recreation, biodiversity, and cultural values.     

Water pricing reform analysis: alternative scenarios

This paper compares alternative transition paths to efficient water pricing. The analysis is based on representative agent model, where two sources of water supply exist: exhaustible groundwater stock and a renewable substitute. Two alternative water pricing reforms are considered: gradual tariff increase and multipart pricing with first block sold at the initial pre-reform tariff and additional water sold at higher prices (block pricing reform). Under block pricing reform, the amount of water offered at low price gradually diminishes. The results of comparative analysis prove that under the same reform time horizon block pricing is preferred to the gradual tariff increase.     

Optimally eating a stochastic cake: a recursive utility approach

In this short paper, uncertainties on resource stock and on technical progress are introduced into an intertemporal equilibrium model of optimal extraction of a non-renewable resource. The representative consumer maximizes a recursive utility function which disentangles between intertemporal elasticity of substitution and risk aversion. A closed-form solution is derived for both the optimal extraction and price paths. The value of the intertemporal elasticity of substitution relative to unity is then crucial in understanding extraction. Moreover, this model leads to a non-renewable resource price following a geometric Brownian motion.     

Species diversity, fishing induced change in carrying capacity and sustainable fisheries management

It is well established in the fisheries management literature that marine ecosystems are complex and marine species depend on one another. As a result, it is important to account for species diversity to ensure sustainable management. In addition, recent research published in the marine sciences literature has provided unequivocal evidence that fishing activities destroy habitats and inhibit production of planktons. This paper illustrates that if a conventional bioeconomic model is employed, an optimum effort policy as opposed to quota appears to result in sustainable management even if fishing impacts carrying capacity. However, the so-called optimum effort may collapse the stock if species diversity is not accounted for. Conversely, if species diversity and the impact of fishing on carrying capacity are considered, neither the equilibrium quota nor effort may guarantee sustainable yield.     

Exhaustible resources,technology choice and industrialization of developing countries

How should the world economy adapt to the increased demand for exhaustible resources from countries like China and India? To address that issue, this paper presents a dynamic model of the world economy with two technologies for production; a resource technology, which uses an exhaustible resource as an input and an alternative technology, which does not. I find that both the time path of resource extraction and the adoption of the alternative technology depend on the optimal allocation of capital across the technologies, and on the size of the capital stock in relation to the resource stock. In particular, if the capital stock is low, only the resource technology is used initially and the alternative technology is adopted with a delay. Next, I use the model to analyze the effects of industrialization of developing countries on the extraction of oil and technology choice for energy production. As a result of industrialization, the alternative technology for energy production is adopted earlier.     

Transboundary marine protected areas

Countries exploiting transboundary natural resources face strong incentives to over-exploit. This basic economic insight has been validated empirically where numerous resources such as water, forests, game, and fisheries are found to be in worse condition than those completely contained in single nations. Attempts to solve this challenge through cross-country cooperation have been largely unsuccessful because competitive extraction is often more attractive than adhering to cooperative agreements. Focusing on the fishery, we explore the game-theoretic economics of an alternative to cooperative arrangements, called a transboundary marine protected area (TMPA), which straddles both countries’ waters. We derive the conditions under which it can improve profits and stock biomass, even in the presence of individually-rational non-cooperation across countries. Strikingly, we find that well-designed TMPAs have the potential to completely overcome non-cooperation across countries; this result is strongest for low growth rate species. A TMPA can earn higher harvest benefits for both countries, increase stocks in both countries, and in many cases, can even reproduce the fully cooperative outcome.     

Endogenous growth with a limited fossil fuel extraction capacity

Campbell (1980) and following authors have discussed a limited resource extraction capacity as an augmentation of the well‐known Hotelling model. We integrate a limited extraction capacity and related investments in the endogenous growth model of Tsur and Zemel (2005) to study its effect on economic development. The capacity constraint gives rise to three effects. On the one hand, higher energy costs and the reallocation of production towards capacity investments decrease production available for consumption, research and/or capital investments (energy costs and reallocation effect). On the other hand, research investments may increase, which boosts available production (research effect). Depending on the capital endowment and the strength of the effects, long‐run consumption may be boosted or depressed. In particular, the capacity constraint may render everlasting consumption growth non‐optimal in a resource‐rich economy. Furthermore, we find that capacity investments may be postponed to later points in time if the capital endowment is high.     

GROUNDWATER MANAGEMENT THROUGH COLLECTIVE PARTICIPATION: WHY SOME INSTITUTIONS SUCCEED AND OTHERS FAIL?

In response to prolonged drought situations, water collectives have been promoted and exist in most water scarce farming regions to help them sustainably manage groundwater resources. However, the sustainability of the collectives itself is prone to groundwater depletion and to the risk of its irreversible future loss. The role of groundwater loss risk in determining the success or failure of groundwater collectives is inadequately understood. In this paper, a stylized dynamic optimization model of institutional participation is developed and results are analyzed for several cases of collective and non‐collective farming behaviour. Results indicate that risk of groundwater loss may increase the tendency to free ride and exacerbate its depletion. This tendency may increase with a larger collective size when there are no deterrence mechanisms in place. However, when staying out threatens institutional stability, it is optimal for the profit maximizing farmer to join the collective and help with groundwater conservation.     

Predators in the market: implications of market interaction on optimal resource management

A two-species bioeconomic model is analyzed, but in contrast to most similar models, there is no biological interaction between the species, only economic. The interaction takes place in the market where the quantity of either species may affect the price of the other. The effects of cross-price elasticities on the optimal steady state and on the optimal paths in the sole-owner case are investigated both analytically (steady states) and numerically (optimal paths). First, it is shown that if the harvest of one species has impact on the price of another species, then this has a positive effect on its steady-state stock. The effect increases with the stock-elasticity in the cost function. Further, in the case of linear demand functions, the steady state outcome depends solely on the sum of the cross-price parameters and not their individual values. Secondly, in the investigation of optimal paths, it is shown that if the harvest of one species has impact on the price of the other, optimal trajectories reach steady state faster for itself and slower for the other species. Further, when cross-price elasticities are sufficiently high, the paths go from being monotonic to feature over- or undershooting.