Input Use and Incentives in the Caribbean Shrimp Fishery: The Case of the Trinidad and Tobago Fleet

This paper examines the economic factors that influence output in the Trinidad and Tobago shrimp fishery using a Generalized Leontief production function. Factors such as output prices and the use of inputs in the fishery are assessed. The artisanal and industrial fleets operate in a largely open-access fishery, which is seasonal. While shrimp is the main targeted species, various fish species are also targeted using gear modifications. It was found that for the artisanal shrimp trawl fleet in Trinidad and Tobago, effort, in terms of trip days, was estimated to have a significant effect on both shrimp and bycatch landings at almost similar levels. The relative price of the two species was not found to be significant, and no annual trends in the production of either was observed. However, the high season for shrimp landings, January to June, was found to have significant inverse effects on shrimp and bycatch landings.Generalized Leontief production function, effort, shrimp, Trinidad and Tobago., Community/Rural/Urban Development, Institutional and Behavioral Economics, International Development, Research Methods/ Statistical Methods, Q21, Q22, C33.,

PRODUCTIVITY GROWTH IN THE CARIBBEAN: A MEASURE OF KEY COMPONENTS

Productivity growth is decomposed into two components: technical change and efficiency change. This assesses their relative importance to the international competitiveness of the agricultural sectors of selected Caribbean countries. A nonparametric programming method is employed to compute Malmquist multifactor productivity indexes, which contrasts the innovation of races of these countries. Keywords: Multifactor productivity, Malmquist indexes, Caribbean agriculture, Relative efficiency, Technical efficiencyMultifactor productivity, Malmquist indexes, Caribbean agriculture, Relative efficiency, Technical efficiency, Productivity Analysis, Research Methods/ Statistical Methods,

Modelling the hepatitis C virus disease burden among injecting drug users in Scotland

A forward projection model was used to estimate the numbers of, both current and former, IDUs who acquired HCV infection and progressed to mild, moderate and severe HCV disease in Glasgow and Scotland between 1960 and 2030. The model was developed initially for Glasgow because more epidemiological information exists for this region, than elsewhere in Scotland, to calibrate model outcomes with local data relating to HCV and its consequence. Insights gained from the model fitting process in Glasgow were then used to extend the model to the rest of Scotland. First, the incidence and cessation of injecting drug use in Glasgow during 1960-2000 were derived through the use of a modified Delphi approach. Instead of the usual iterative process to refine experts’ estimates, the elicitation of IDU incidence and cessation provided an opportunity to combine these data and examine coherence with capture-recapture IDU prevalence estimates. Coherent estimates indicated that incidence (median: 28 to 49) and cessation (1 to 24%) remained low and stable during 1960-1975, rose steeply between 1975-1985 (incidence from 49 to 1,335; cessation from 2% to 6%), and by 2000 there had been a decline in incidence (1,195) but a further rise in cessation (15%). Secondly, stochastic simulation was used to model the transmission of HCV among current IDUs in Glasgow, according to their injecting risk behaviours, and estimate the past incidence of HCV infection. The model that considered higher infectivity during acute viraemia following infection produced seroprevalences (median: 62-72%) and incidences (18-30 per 100 susceptible injector-years) consistent with observed data during the 1990s. The annual number of new HCV infections among current IDUs in Glasgow was estimated to be low during 1960-1976 (median: 10-60), rise steeply during 1960-1976 (median: 10-60), rise steeply during the early 1980s to peak in 1985 (1,120), stabilise during 1991-1997 (510-610) and rise again during 1998-2000 (710-780). Scenario analyses indicated that potentially as many as 4,500 HCV infections (10th and 90th percentiles: 2,400-7,700) had been prevented in Glasgow during 1988-2000 as a result of harm-reduction measures. Scenario analyses also permitted the gauging of changes in risk behaviours required to effect appreciable reductions in the incidence of HCV infection. Incidence can be successfully reduced if IDUs who, unavoidably, share needles/syringes confine their borrowing to one person; with this strategy alone, an estimated 5,300 HCV infections (10th and 90th percentiles: 4,100-6,700) could have been averted in Glasgow during 1988-2000. Such insights will inform those responsible for developing new ways to prevent HCV transmission among IDU populations. Thirdly, linkage of laboratory data on diagnosed HCV antibody positive persons in Scotland to clinical data from hospital and death records provided a unique national epidemiological dataset to estimate the number who had progressed to severe HCV disease

Strategies for the treatment of Hepatitis C in an era of interferon-free therapies: what public health outcomes do we value most?

Objective: The expense of new therapies for HCV infection may force health systems to prioritise the treatment of certain patient groups over others. Our objective was to forecast the population impact of possible prioritisation strategies for the resource-rich setting of Scotland. Design: We created a dynamic Markov simulation model to reflect the HCV-infected population in Scotland. We determined trends in key outcomes (e.g. incident cases of chronic infection and severe liver morbidity (SLM)) until the year 2030, according to treatment strategies involving prioritising, either: (A) persons with moderate/advanced fibrosis or (B) persons who inject drugs (PWID). Results: Continuing to treat the same number of patients with the same characteristics will give rise to a fall in incident infection (from 600 cases in 2015 to 440 in 2030) and a fall in SLM (from 195 cases in 2015 to 145 in 2030). Doubling treatment-uptake and prioritising PWID will reduce incident infection to negligible levels (<50 cases per year) by 2025, while SLM will stabilise (at 70–75 cases per year) in 2028. Alternatively, doubling the number of patients treated, but, instead, prioritising persons with moderate/advanced fibrosis will reduce incident infection less favourably (only to 280 cases in 2030), but SLM will stabilise by 2023 (i.e. earlier than any competing strategy). Conclusions: Prioritising treatment uptake among PWID will substantially impact incident transmission, however, this approach foregoes the optimal impact on SLM. Conversely, targeting those with moderate/advanced fibrosis has the greatest impact on SLM but is suboptimal in terms of averting incident infection

Commentary : missing targets on drugs-related deaths, and a Scottish paradox

The 10-year drug strategy for England and Wales was published in February 2008. It dropped drugs-related deaths (DRDs) as a key performance indicator. Scotland retained a necessary strong focus on DRDs. Scotland's DRDs numbered 1006 in 2000–02 and 1009 in 2003–05. The previous Scottish administration's claim that its number of current injectors had decreased substantially between 2000 and 2003 implied, paradoxically, that their DRD rate would have to have increased. Worse was to come: Scotland's DRDs had increased to 876 in 2006 + 2007. We analyse UK's DRDs by sex and age-group to reveal temporal trends (2000–02 versus 2003–05 versus 2006 + 2007) with different public health and epidemiological implications. We also address the above Scottish paradox and assess, by age-group, how consistent Scotland's 876 DRDs in 2006 + 2007 are with Scottish injectors’ DRD rate in 2003–05 of around 1 per 100 injector-years. Public health success in the UK in reducing DRDs at younger ages should not be overshadowed by the late consequence in terms of older-age DRDs of UK's injector epidemics; in the early 1980s in Scotland, and late 1980s in England and Wales. Targets for reducing DRDs should pay heed to UK's injector epidemics

Modeling the initiation of others into injection drug use, using data from 2,500 injectors surveyed in Scotland during 2008-2009

The prevalence of injection drug use has been of especial interest for assessment of the impact of blood-borne viruses. However, the incidence of injection drug use has been underresearched. Our 2-fold aim in this study was to estimate 1) how many other persons, per annum, an injection drug user (IDU) has the equivalent of full responsibility (EFR) for initiating into injection drug use and 2) the consequences for IDUs' replacement rate. EFR initiation rates are strongly associated with incarceration history, so that our analysis of IDUs' replacement rate must incorporate when, in their injecting career, IDUs were first incarcerated. To do so, we have first to estimate piecewise constant incarceration rates in conjunction with EFR initiation rates, which are then combined with rates of cessation from injecting to model IDUs' replacement rate over their injecting career, analogous to the reproduction number of an epidemic model. We apply our approach to Scotland's IDUs, using over 2,500 anonymous injector participants who were interviewed in Scotland's Needle Exchange Surveillance Initiative during 2008-2009. Our approach was made possible by the inclusion of key questions about initiations. Finally, we extend our model to include an immediate quit rate, as a reasoned compensation for higher-than-expected replacement rates, and we estimate how high initiates' quit rate should be for IDUs' replacement rate to be 1

Exploring associations between perceived HCV status and injecting risk behaviors among recent initiates to injecting drug use in Glasgow

The aim of this study was to explore the influence of testing for hepatitis C virus (HCV) and perceived HCV status on injecting risk behavior. A cross-sectional, community-wide survey was undertaken at multiple sites throughout Greater Glasgow during 2001-2002. Four hundred ninety-seven injecting drug users (IDUs) consented to participate and were interviewed using a structured questionnaire to ascertain HCV test history and injecting risk behavior. The average age of participants was 27 years and the majority of the sample were male (70.4%). Participants had been injecting for an average duration of 2.5 years. Logistic regression analysis revealed no significant associations between having been tested and injecting risk behavior. After adjustment for potential confounding variables, HCV-negatives were significantly less likely to borrow needles/syringes and spoons or filters as compared with unawares and were significantly less likely to borrow spoons or filters as compared with HCV-positives. Due to the cross-sectional design of the study, it is uncertain whether this reduction in risk behavior could be attributed to perception of HCV status. Further research is recommended to consolidate the evidence for this relationship

Harm reduction among injecting drug users - evidence of effectiveness

This chapter synthesises and evaluates the available direct evidence relating to the impact of needle and syringe programmes (NSPs), opioid substitution treatment (OST), drug consumption rooms (DCRs), and peer naloxone distribution (PND) on HIV/hepatitis C (HCV) incidence/prevalence, injecting risk behaviour and overdose-related mortality. To achieve this, we conducted a review of reviews; a systematic and explicit method used to identify, select and critically appraise relevant findings from secondary level research (systematic reviews and/or meta-analyses) into an evidence briefing. In the absence of high-quality reviews, appraisal of the evidence was supplemented with a targeted review of the primary literature. We find that there is sufficient review-level evidence that OST reduces HIV transmission, while the evidence in support of NSPs reducing HIV transmission is more tentative, and for DCRs currently insufficient. There is tentative evidence that OST has limited effectiveness in reducing HCV transmission, and insufficient evidence to support or discount NSPs or DCRs' ability to reduce HCV transmission. There is sufficient review-level evidence that NSPs, OST and DCRs reduce self-reported injecting risk behaviour. There is sufficient review evidence that OST reduces risk of overdose mortality, but insufficient evidence to support or discount the effect of DCRs or PND on overdose deaths at the community level. Our review shows evidence in support of a variety of harm reduction interventions but highlights an uneven presence of high-quality review evidence. Future evaluation of harm reduction programmes should prioritise methodologically robust study designs

Violence, legitimacy, and prophecy: Nuer struggles with uncertainty in South Sudan

Contemporary South Sudanese Nuer prophets play powerful roles in interpreting the moral limits of lethal violence and weighing the legitimacy claims of rival government leaders. Their activities remain largely invisible to external observers investigating the making and unmaking of fragile states. Focusing on South Sudan’s tumultuous 2005–14 period, we reveal these hidden dynamics through analysis of the two most-powerful living western Nuer prophets. Gatdeang Dit, a male prophet of the divinity Deng, rejects all forms of violent aggression and fosters relations of peace and intermarriage with Dinka neighbors. Nyachol, a female prophet of Maani, inspires thousands of armed Nuer youth to retaliate against Dinka cattle raiders and other external threats while insisting on purification for Nuer–Nuer homicides. Despite their differences, both prophets invoke God’s superior powers to push back against the simplified, secularized, and objectified forms of violence glorified by rival government elites. [prophecy, government, violence, legitimacy, uncertainty, Nuer, South Sudan