ISSUES IN HAZARDOUS WASTE MANAGEMENT: DISCUSSION

Resource /Energy Economics and Policy,

Capital Dynamics in the North Sea Herring Fishery

Dynamic adjustment is an integral part of natural resource economics. Commonly, capital is assumed to respond instantaneously to changes in profits, while in reality adjustment may take place only with a time lag. In this paper, an empirical analysis of capital (boat) dynamics in the North Sea herring fishery is undertaken. A discrete time model is formulated to model decisions of boats to enter or exit the fishery. A lagged model is specified to reflect adjustment time to changes in profits. The empirical results indicate that fleet adjustment in this fishery primarily depends on current period profits and that the opportunity cost may depend on returns in the alternative fishery. Inclusion of lagged variables to account for the construction time for new boats, showed only a small improvement in the statistical fit. Moreover, the results did not support a hypothesis that entry in response to positive profits is more elastic than exit due to negative profits.Environmental Economics and Policy, Production Economics, Resource /Energy Economics and Policy,

Wilderness: Options to Preserve, Extract or Develop

WP 1998-01 March 199

Optimizing The Riparian Buffer: Harold Brook In The Skaneateles Lake Watershed, New York

The use of riparian land buffers to protect water quality for human consumption and wildlife habitat has become an important conservation tool of both government and non-government agencies. The funds available to acquire private lands for riparian buffers are limited, however, and not all land contributes to water quality goals in the same way. Conservation agencies must therefore identify effective ways to allocate their scarce budgets in heterogeneous landscapes. We demonstrate how the acquisition of land for a riparian buffer can be viewed as a binary optimization problem and we apply the resulting model to a case study in New York (JEL Q15, Q25). Working Paper # 2002-00

A BIOECONOMIC ANALYSIS OF THE NORTHERN ANCHOVY

A simple bioeconomic model was specified and estimated for the central subpopulation of the northern anchovy (Engraulis mordax). Net population growth was described by a power function and harvest by the U. S. reduction fleet was modelled by an exponential production function. When incorporated into a bioeconomic model they allowed the derivation of two explicit functions, Y = Ö(X) and Y = Ø(X) which could be used to depict the bioeconomic optimum. The roots of Ö(X) have important economic interpretations and can be used to characterize the economic status of the fishery. The positively-sloped segment of the Ö(X) curve may be used as an approximately-optimal adaptive management policy. For the set of bioeconomic parameters circa 1990, anchovy biomass would need to increase to about 1 million metric tons before arousing the economic interest of the wetfish fleet. Alternatively, a price/cost ratio of 0.6 or more would imply positive net revenues at a biomass of 350,000 metric tons. The current price/cost ratio may be as low as 0.1 and the current estimate of biomass is about 300,000 metric tons. Thus, unless there is a dramatic increase in the demand for oil and fish meal or a spectacular increase in biomass, it seems unlikely that there will be a resurgence in the reduction fishery for anchovy in the near future.Resource /Energy Economics and Policy,

ECONOMIC STRATEGIES FOR COEVOLUTION: PARKS, BUFFER ZONES AND BIODIVERSITY

The creation of parks and preserves in less developed countries is seen as an important step in preserving biodiversity and genetic information (Dixon and Sherman 1990). The establishment of a park or preserve, however, is often seen as a threat by rural residents if they are denied access to areas where hunting, gathering or small scale agricultural provided them with food, fuel or marketable products. In a series of papers Norgaard (1981, 1984 and 1985) advocates development strategies that promote coevolution of socioeconomic and ecological systems. In this dynamic context, coevolution might be defined by a set of trajectories describing economic welfare and biodiversity that remain within "acceptable" bounds over some future horizon. (1) What are some possible measures for economic welfare and biodiversity? (2) How might one identify the scale and location of hunting, gathering and agricultural activities within a buffer zone to a park or preserve that would qualify as coevolutionary? (3) How might one optimize over the set of coevolutionary strategies? A methodology is proposed to address these questions and to explore the economic incentives that might support a coevolutionary strategy in the buffer zone to a park or preserve.Resource /Energy Economics and Policy,

The Economic Threshold With a Stochastic Pest Population: An Application to the European Red Mite

WP 1996-09 August 199

Heteroleptic samarium(III) halide complexes probed by fluorescence-detected L3-edge X-ray absorption spectroscopy

Addition of various oxidants to the near-linear Sm(II) complex [Sm(N††)2] (1), where N†† is the bulky bis(triisopropylsilyl)amide ligand {N(SiiPr3)2}, afforded a family of heteroleptic three-coordinate Sm(III) halide complexes, [Sm(N††)2(X)] (X = F, 2-F; Cl, 2-Cl; Br, 2-Br; I, 2-I). In addition, the trinuclear cluster [{Sm(N††)}3(μ2-I)3(μ3-I)2] (3), which formally contains one Sm(II) and two Sm(III) centres, was isolated during the synthesis of 2-I. Complexes 2-X are remarkably stable towards ligand redistribution, which is often a facile process for heteroleptic complexes of smaller monodentate ligands in lanthanide chemistry, including the related bis(trimethylsilyl)amide {N(SiMe3)2} (N′′). Complexes 2-X and 3 have been characterised by single crystal X-ray diffraction, elemental analysis, multinuclear NMR, FTIR and electronic spectroscopy. The Lα1 fluorescence-detected X-ray absorption spectrum recorded at the Sm L3-edge for 2-X exhibited a resolved pre-edge peak defined as an envelope quadrupole-allowed 2p → 4f transition. The X-ray absorption spectral features were successfully reproduced using time-dependent density functional theoretical (TD-DFT) calculations that synergistically supports the experimental observations as well as the theoretical model upon which the electronic structure and bonding in lanthanide complexes is derived

Constant proportion harvest policies: Dynamic implications in the Pacific halibut and Atlantic cod fisheries

a b s t r a c t Overfishing, pollution and other environmental factors have greatly reduced commercially valuable stocks of fish. In a 2006 Science article, a group of ecologists and economists warned that the world may run out of seafood from natural stocks if overfishing continues at current rates. In this paper, we explore the interaction between a constant proportion harvest policy and recruitment dynamics. We examine the discrete-time constant proportion harvest policy discussed in Ang et al. We focus on constant proportion policies (CPPs). CPPs have the potential to stabilize complex overcompensatory stock dynamics, with or without the Allee effect, provided the rates of harvest stay below a threshold. If that threshold is exceeded, CPPs are known to result in the sudden collapse of a fish stock when stock recruitment exhibits the Allee effect. In case studies, we analyze CPPs as they might be applied to Gulf of Alaska Pacific halibut fishery and the Georges Bank Atlantic cod fishery based on harvest rates from 1975 to 2007. The best fit models suggest that, under high fishing mortalities, the halibut fishery is vulnerable to sudden population collapse while the cod fishery is vulnerable to steady decline to zero. The models also suggest that CPP with mean harvesting levels from the last 30 years can be effective at preventing collapse in the halibut fishery, but these same policies would lead to steady decline to zero in the Atlantic cod fishery. We observe that the likelihood of collapse in both fisheries increases with increased stochasticity (for example, weather variability) as predicted by models of global climate change

Optimizing sequencing protocols for leaderboard metagenomics by combining long and short reads.

As metagenomic studies move to increasing numbers of samples, communities like the human gut may benefit more from the assembly of abundant microbes in many samples, rather than the exhaustive assembly of fewer samples. We term this approach leaderboard metagenome sequencing. To explore protocol optimization for leaderboard metagenomics in real samples, we introduce a benchmark of library prep and sequencing using internal references generated by synthetic long-read technology, allowing us to evaluate high-throughput library preparation methods against gold-standard reference genomes derived from the samples themselves. We introduce a low-cost protocol for high-throughput library preparation and sequencing