Protecting Marine Biodiversity: A Comparison of Individual Habitat Quotas (IHQs) and Marine Protected Areas

Fisheries managers in the United States are required to identify and mitigate the adverse impacts of fishing activity on essential fish habitat (EFH). There are additional concerns that the viability of noncommercial species, animals that are habitat dependent and/or are themselves constituents of fishery habitat may still be threatened. We consider a cap-and-trade system for habitat conservation, individual habitat quotas for fisheries, to achieve habitat conservation and species protection goals cost effectively. Individual quotas of habitat impact units (HIUs) would be distributed to fishers with an aggregate quota set to maintain a target habitat “stock” of EFH conservation. Using a dynamic, spatially explicit fishery simulation model we explore the efficiency and cost effectiveness of an IHQ policy versus alternative marine protected area (MPA) configurations, at reducing the risk of extinguishing a habitat dependent species of unknown spatial distribution. Our findings indicate that an IHQ policy with a conservatively established habitat target is better suited to the protection of non-target species than a rotating or fixed MPA policy.Fisheries management, Individual transferable quota, ITQ, Individual habitat quota, IHQ, Essential fish habitat, EFH, Marine protected areas, MPA, Non-target species

The Impact of Interstate Highways on Land Use Conversion

Between 1945 and 2007, the United States lost 19.3 % of its agricultural land. Over the same time period, the construction of the 42,500 mile interstate highway system lowered transportation costs and opened large tracts of land for development. This paper assesses the impact of the interstate highway system on agricultural land loss in Georgia and uses the empirical estimates to simulate agricultural land loss resulting from the construction of additional interstate highways. Using a historical data set of agricultural land and interstate highway mileage, empirical estimates indicate that each additional mile of interstate highway reduces agricultural land by 468 acres. The impact of interstate highways is heterogeneous across initial level of county development. Urban counties convert 70 % more land than the full sample estimates. Simulation results show that additions to the interstate system create further loss of agricultural land. The results imply that future conservation programs need to consider how to mitigate the impact of the interstate highway system

Drive ‘Til You Qualify: Credit Quality and Household Location

A deeper understanding of the credit-sorting process is essential when considering the extent to which home foreclosures are driven by price contagion or an underlying spatial pattern of mortgage quality. Adapting household location theory, we find that credit constrained households follow “drive-\u27til-you-qualify” behavior leading to rising credit quality with distance from the CBD while unconstrained households exhibit declining credit quality. Individual level mortgage loan-to-income data for the 100 largest MSAs show credit constrained behavior either throughout the urban area or concentrated in the suburbs. Meta analysis of the credit sorting estimates identify MSA characteristics associated with each pattern

A Spatial Model of Dolphin Avoidance in the Eastern Tropical Pacific Ocean

This paper examines the impact of dolphin-safe eco-labeling and how it fundamentally altered the spatial distribution of fishing effort and fishermen's willingness to pay to avoid dolphins. To do this, a dynamic discrete choice econometric model is applied to the Eastern Tropical Pacific tuna fishery. This econometric approach combines a dynamic programming component with the static discrete site choice model. This estimator couples the current period projected profits associated with fishing a specific site with the value of all future location choices on the cruise, assuming choices are made optimally. The key feature of this model is that it recovers behavioral parameters and solves the dynamic programming problem recursively. The dynamic site choice model reveals a markedly higher impact on producers as compared to the commonly used static model following the labeling regime. Further, in all but a few cases the common practice in dynamic choice models of setting discount factors equal to one is rejected.Environmental Economics and Policy,

Validierung dreidimensionaler MRT-basierter Knorpelvolumen und -dickenmessungen mit der CT-Arthrographie

Ziel der Arbeit war die Validierung dreidimensionaler Volumen- und Dickenmessungen des Kniegelenkknorpels in der Magnetresonanztomographie im Vergleich zur CT-Arthrographie. Acht frische Kniegelenkpräparate (Alter 35 bis 64 Jahre) wurden mit einer hochauflösenden, fettunterdrückten FLASH-3D-Sequenz untersucht und sagittale Schnittbilder mit einer Auflösung von 2 mm * 0,31 mm * 0,31 mm angefertigt. Anschließend wurden bei gleicher Auflösung zwei sagittale Datensätze mittels CT-Arthrographie erhoben (Kontrastmittel: Ultravist 300, Schering AG; 80 bis 150 ml), wobei das Knie zwischen diesen Aufnahmen repositioniert wurde. Auf Basis von 3D-Rekonstruktionen wurde das Knorpelvolumen und, mittels eines 3D-Minimaldistanz-Algorithmus, die Knorpeldickenverteilung an der Patella, am Femur und an der Tibia bestimmt. Die Ergebnisse der beiden Methoden wurden statistisch verglichen. Wir finden eine hohe Übereinstimmung des Knorpelvolumens und der Knorpeldicke zwischen MRT und der CT-Arthrographie. Das Volumen wurde in der MRT relativ zur CT-Arthrographie um durchschnittlich 3,3 % überschätzt. Zwischen den beiden CT-arthrographischen Datensätzen ergab sich ein Unterschied von 3,6 %. Die maximale Knorpel-dicke wurde in der MRT um durchschnittlich 0,23 Dickenintervalle zu 0,5 mm unterschätzt. Der Unterschied zwischen den CT-Arthrographien lag bei 0,05 Dickenintervallen. An keiner der Gelenkflächen ergab sich eine statistisch signifikante Abweichung zwischen den Verfahren. Die Ergebnisse legen nahe, dass bei Verwendung einer fettunterdrückten FLASH-Sequenz mit hoher Auflösung und dreidimensionaler Bildverarbeitungsmethode sowohl das Knorpelvolumen als auch die Knorpeldicke mit der MRT nicht-invasiv und mit großer Genauigkeit bestimmt werden können. Damit steht eine valide, nicht-invasive Technik zur Verfügung, mit der die Morphologie des Gelenkes unter physiologischen und pathophysiologischen Zuständen am Lebenden charakterisiert werden kann

A history of Bancroft, Nebraska

In the mid-nineteenth century, the land from the Missouri River to the ninety-eighth meridian was the home of the Omaha Indians who had roamed the hills of northeast Nebraska since the seventeeth century. The march of the whites, however, had in 1854 pressured the tribe into ceding all their land in Nebraska with the exception of 300,000 acres which they retained in the northeast section of the state. this reservation bordered on the Logan valley in northeast Cuming County. The Logan Creek was surrounded by miles of rich prairie just as it had been for centuries. But all of this was to change. The virgin land was soon to feel the plow

Estimating Heterogeneous Primal Capacity and Capacity Utilization Measures in a Multi-Species Fishery

We use a stochastic production frontier model to investigate the presence of heterogeneous production and its impact on fleet capacity and capacity utilization in a multi-species fishery. Furthermore, we propose a new fleet capacity estimate that incorporates complete information on the stochastic differences between each vessel-specific technical efficiency distribution. Results indicate that ignoring heterogeneity in production technologies within a multi-species fishery, as well as the complete distribution of a vessel's technical efficiency score, may yield erroneous fleet-wide production profiles and estimates of capacity.Resource /Energy Economics and Policy,