Global markets and the commons: The role of imports in the US wild-caught shrimp market

The commons literature focuses heavily on rules and the behavior of resource users but places less emphasis on the returns to individual effort. However, for most resource settings, market conditions and associated resource prices are key drivers of exploitation effort. In a globalized world, import competition can strongly influence the incentives for individual resource users, a topic largely unexplored in the commons literature. Import competition is especially salient for seafood, one of the most internationally traded food groups. We analyze the US shrimp market, which was once dominated by domestic catches but is now mostly supplied by imports. For domestic producers (users of the commons), lower revenues result, while US consumers eat more shrimp at lower prices. Globalization changed the sources of price risk and compensation that domestic producers face and altered incentives to exploit the commons. In a market dominated by domestic supply shocks, the price response to a shock moderates the effect on revenue and effort. In a market dominated by imports, domestic shocks are buffered by import adjustments, while price movements are determined by global shocks. Despite losses for the domestic fishery, globalization creates new incentives to coordinate effort and capture price premiums determined in the global market.publishedVersio

Charge Conjugation from Space-Time Inversion

We show that the CPT group of the Dirac field emerges naturally from the PT and P (or T) subgroups of the Lorentz group.Comment: 4 pages, no figure

Cost-effectiveness of Physical Therapy vs Intra-articular Glucocorticoid Injection for Knee Osteoarthritis: A Secondary Analysis From a Randomized Clinical Trial

Importance: Physical therapy and glucocorticoid injections are initial treatment options for knee osteoarthritis, but available data indicate that most patients receive one or the other, suggesting they may be competing interventions. The initial cost difference for treatment can be substantial, with physical therapy often being more expensive at the outset, and cost-effectiveness analysis can aid patients and clinicians in making decisions. Objective: To investigate the incremental cost-effectiveness between physical therapy and intra-articular glucocorticoid injection as initial treatment strategies for knee osteoarthritis. Design, setting, and participants: This economic evaluation is a secondary analysis of a randomized clinical trial performed from October 1, 2012, to May 4, 2017. Health economists were blinded to study outcomes and treatment allocation. A randomized sample of patients seen in primary care and physical therapy clinics with a radiographically confirmed diagnosis of knee osteoarthritis were evaluated from the clinical trial with 96.2% follow-up at 1 year. Interventions: Physical therapy or glucocorticoid injection. Main outcomes and measures: The main outcome was incremental cost-effectiveness between 2 alternative treatments. Acceptability curves of bootstrapped incremental cost-effectiveness ratios (ICERs) were used to identify the proportion of ICERs under the specific willingness-to-pay level ($50 000-$100 000). Health care system costs (total and knee related) and health-related quality-of-life based on quality-adjusted life-years (QALYs) were obtained. Results: A total of 156 participants (mean [SD] age, 56.1 [8.7] years; 81 [51.9%] male) were randomized 1:1 and followed up for 1 year. Mean (SD) 1-year knee-related medical costs were $2113 ($4224) in the glucocorticoid injection group and $2131 ($1015) in the physical therapy group. The mean difference in QALY significantly favored physical therapy at 1 year (0.076; 95% CI, 0.02-0.126; P = .003). Physical therapy was the more cost-effective intervention, with an ICER of $8103 for knee-related medical costs, with a 99.2$100 000. Conclusions and relevance: A course of physical therapy was cost-effective compared with a course of glucocorticoid injections for patients with knee osteoarthritis. These results suggest that, although the initial cost of delivering physical therapy may be higher than an initial course of glucocorticoid injections, 1-year total knee-related costs are equivalent, and greater improvement in QALYs may justify the initial higher costs. Trial registration: ClinicalTrials.gov Identifier: NCT0142715

Fish Is Food - The FAO’s Fish Price Index

World food prices hit an all-time high in February 2011 and are still almost two and a half times those of 2000. Although three billion people worldwide use seafood as a key source of animal protein, the Food and Agriculture Organization (FAO) of the United Nations–which compiles prices for other major food categories–has not tracked seafood prices. We fill this gap by developing an index of global seafood prices that can help to understand food crises and may assist in averting them. The fish price index (FPI) relies on trade statistics because seafood is heavily traded internationally, exposing non-traded seafood to price competition from imports and exports. Easily updated trade data can thus proxy for domestic seafood prices that are difficult to observe in many regions and costly to update with global coverage. Calculations of the extent of price competition in different countries support the plausibility of reliance on trade data. Overall, the FPI shows less volatility and fewer price spikes than other food price indices including oils, cereals, and dairy. The FPI generally reflects seafood scarcity, but it can also be separated into indices by production technology, fish species, or region. Splitting FPI into capture fisheries and aquaculture suggests increased scarcity of capture fishery resources in recent years, but also growth in aquaculture that is keeping pace with demand. Regionally, seafood price volatility varies, and some prices are negatively correlated. These patterns hint that regional supply shocks are consequential for seafood prices in spite of the high degree of seafood tradability

Assessment of the economic performance of the seabream and seabass aquaculture industry in the European Union

Production of gilthead seabream (Sparus aurata) and European seabass (Dicentrarchus labrax) is the second most important aquaculture industry in the European Union in value terms. During the last 10 years, the industry has experienced a process of industry concentration with the aim to overcome efficiency and profitability issues. However, the economic performance of the companies is still in general rather poor. The present work analyzes the economic performance of EU seabream and seabass companies in the period 2008?2016. The work is the first study to analyze companies? profitability in the EU as a whole, by country and company size, using economic and financial data extracted from companies? annual accounts. Based on the results, the study discusses the improvement of production and business profitability in recent years and the different factors that may have caused it, as well as the challenges and threats that seabream and seabass companies will have to face in order to achieve economic sustainability.This research was undertaken under the MedAID project, which has received funding from the European Union's Horizon 2020 Research and Innovation Programme under grant agreement no 727315 (http://www.medaid-h2020.eu/)

Seafood prices reveal impacts of a major ecological disturbance

Coastal hypoxia (dissolved oxygen ≤ 2 mg/L) is a growing problem worldwide that threatens marine ecosystem services, but little is known about economic effects on fisheries. Here, we provide evidence that hypoxia causes economic impacts on a major fishery. Ecological studies of hypoxia and marine fauna suggest multiple mechanisms through which hypoxia can skew a population’s size distribution toward smaller individuals. These mechanisms produce sharp predictions about changes in seafood markets. Hypoxia is hypothesized to decrease the quantity of large shrimp relative to small shrimp and increase the price of large shrimp relative to small shrimp. We test these hypotheses using time series of size-based prices. Naive quantity-based models using treatment/control comparisons in hypoxic and nonhypoxic areas produce null results, but we find strong evidence of the hypothesized effects in the relative prices: Hypoxia increases the relative price of large shrimp compared with small shrimp. The effects of fuel prices provide supporting evidence. Empirical models of fishing effort and bioeconomic simulations explain why quantifying effects of hypoxia on fisheries using quantity data has been inconclusive. Specifically, spatial-dynamic feedbacks across the natural system (the fish stock) and human system (the mobile fishing fleet) confound “treated” and “control” areas. Consequently, analyses of price data, which rely on a market counterfactual, are able to reveal effects of the ecological disturbance that are obscured in quantity data. Our results are an important step toward quantifying the economic value of reduced upstream nutrient loading in the Mississippi Basin and are broadly applicable to other coupled human-natural systems.publishedVersio

Will a catch share for whales improve social welfare?

We critique a proposal to use catch shares to manage transboundary wildlife resources with potentially high non-extractive values, and we focus on the case of whales. Because whales are impure public goods, a policy that fails to capture all nonmarket benefits (due to free riding) could lead to a suboptimal outcome. Even if free riding were overcome, whale shares would face four implementation challenges. First, a whale share could legitimize the international trade in whale meat and expand the whale meat market. Second, a legal whale trade creates monitoring and enforcement challenges similar to those of organizations that manage highly migratory species such as tuna. Third, a whale share could create a new political economy of management that changes incentives and increases costs for nongovernmental organizations (NGOs) to achieve the current level of conservation. Fourth, a whale share program creates new logistical challenges for quota definition and allocation regardless of whether the market for whale products expands or contracts. Each of these issues, if left unaddressed, could result in lower overall welfare for society than under the status quo