The effects of environmental perturbation and measurement error on estimates of the shape parameter in the theta-logistic model of population regulation

The theta-logistic is a widely used generalisation of the logistic model of regulated biological processes which is used in particular to model population regulation. Then the parameter theta gives the shape of the relationship between per-capita population growth rate and population size. Estimation of theta from population counts is however subject to bias, particularly when there are measurement errors. Here we identify factors disposing towards accurate estimation of theta by simulation of populations regulated according to the theta-logistic model. Factors investigated were measurement error, environmental perturbation and length of time series. Large measurement errors bias estimates of theta towards zero. Where estimated theta is close to zero, the estimated annual return rate may help resolve whether this is due to bias. Environmental perturbations help yield unbiased estimates of theta. Where environmental perturbations are large, estimates of theta are likely to be reliable even when measurement errors are also large. By contrast where the environment is relatively constant, unbiased estimates of theta can only be obtained if populations are counted precisely Our results have practical conclusions for the design of long-term population surveys. Estimation of the precision of population counts would be valuable, and could be achieved in practice by repeating counts in at least some years. Increasing the length of time series beyond ten or 20 years yields only small benefits. if populations are measured with appropriate accuracy, given the level of environmental perturbation, unbiased estimates can be obtained from relatively short censuses. These conclusions are optimistic for estimation of theta. (C) 2008 Elsevier B.V All rights reserved.

Are the debates on water privatization missing the point? Experiences from Africa, Asia and Latin America

This paper has two principal aims: first, to unravel some of the arguments mobilized in the controversial privatization debate, and second, to review the scale and nature of private sector provision of water and sanitation in Africa, Asia and Latin America. Despite being vigorously promoted in the policy arena and having been implemented in several countries in the South in the 1990s, privatization has achieved neither the scale nor benefits anticipated. In particular, the paper is pessimistic about the role that privatization can play in achieving the Millennium Development Goals of halving the number of people without access to water and sanitation by 2015. This is not because of some inherent contradiction between private profits and the public good, but because neither publicly nor privately operated utilities are well suited to serving the majority of low-income households with inadequate water and sanitation, and because many of the barriers to service provision in poor settlements can persist whether water and sanitation utilities are publicly or privately operated. This is not to say that well-governed localities should not choose to involve private companies in water and sanitation provision, but it does imply that there is no justification for international agencies and agreements to actively promote greater private sector participation on the grounds that it can significantly reduce deficiencies in water and sanitation services in the South.

Beyond the American century: Walter Lippmann and American grand strategy, 1943-1950

As the United States became a world Power, journalist and intellectual Walter Lippmann feared that it would become its own worst enemy. During and after the Second World War, he tried to steer the country towards coherent statecraft, to define the national interest and the limits of power, and give geopolitical expression to the role of the United States as the core of an Atlantic strategic system. But in response to world war, the Truman Doctrine, and the Korean War, he became pessimistic about the country's ability to conduct strategy effectively. In the prophetic tradition, he believed that a fatal symbiosis between America's growing strength and domestic politics led it towards crisis. Though at times ahistorical, Lippmann's concept of strategy deserves attention for its dialogue between power and identity, for its questioning of “ends” as well as means, and for its focus on the danger of self-defeating behaviour.

Changing climate and the Irish landscape

The impacts of current and future changes in climate have been investigated for Irish vegetation. Warming has been observed over the last two decades, with impacts that are also strongly influenced by natural oscillations of the surrounding ocean, seen as fluctuations in the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. Satellite observations show that vegetation greenness increases in warmer years, a feature mirrored by increases in net ecosystem production observed for a grassland and a plantation forest. An ensemble of general circulation model simulations of future climates indicate temperature rises over the twenty-first century ranging from 1°C to 7°C, depending on future scenarios of greenhouse gas emissions. Net primary production is simulated to increase under all scenarios, due to the positive impacts of rising temperature, a modest rise of precipitation and rising carbon dioxide concentrations. In an optimistic scenario of reducing future emissions, CO2 concentration is simulated to flatten from about 2070, although temperatures continue to increase. Under this scenario Ireland could become a source of carbon, whereas under all other emission scenarios Ireland is a sink for carbon that may increase by up to three-fold over the twenty-first century. A likely and unavoidable impact of changing climate is the arrival of alien plant species, which may disrupt ecosystems and exert negative impacts on native biodiversity. Alien species arrive continually, with about 250 dated arrivals in the twentieth century. A simulation model indicates that this rate of alien arrival may increase by anything between two and ten times, dependent on the future climatic scenario, by 2050. Which alien species may become severely disruptive is, however, not known.

Estimating reliability and resolution of probability forecasts through decomposition of the empirical score

References (20)Cited By (1)Export CitationAboutAbstract Proper scoring rules provide a useful means to evaluate probabilistic forecasts. Independent from scoring rules, it has been argued that reliability and resolution are desirable forecast attributes. The mathematical expectation value of the score allows for a decomposition into reliability and resolution related terms, demonstrating a relationship between scoring rules and reliability/resolution. A similar decomposition holds for the empirical (i.e. sample average) score over an archive of forecast–observation pairs. This empirical decomposition though provides a too optimistic estimate of the potential score (i.e. the optimum score which could be obtained through recalibration), showing that a forecast assessment based solely on the empirical resolution and reliability terms will be misleading. The differences between the theoretical and empirical decomposition are investigated, and specific recommendations are given how to obtain better estimators of reliability and resolution in the case of the Brier and Ignorance scoring rule.

Forecasting economic and financial time series with non-linear models

In this paper we discuss the current state-of-the-art in estimating, evaluating, and selecting among non-linear forecasting models for economic and financial time series. We review theoretical and empirical issues, including predictive density, interval and point evaluation and model selection, loss functions, data-mining, and aggregation. In addition, we argue that although the evidence in favor of constructing forecasts using non-linear models is rather sparse, there is reason to be optimistic. However, much remains to be done. Finally, we outline a variety of topics for future research, and discuss a number of areas which have received considerable attention in the recent literature, but where many questions remain.

Fairness quality: the role of fairness in a social and ethically oriented marketing landscape

Research into the dark side of customer management and marketing is progressively growing. The marketing landscape today is dominated with suspicion and distrust as a result of practices that include hidden fees, deception and information mishandling. In such a pessimistic economy, marketers must reconceptualise the notion of fairness in marketing and customer management, so that the progress of sophisticated customisation schemes and advancements in marketing can flourish, avoiding further control and imposed regulation. In this article, emerging research is drawn to suggest that existing quality measures of marketing activities, including service, relationships and experiences may not be comprehensive in measuring the relevant things in the social and ethically oriented marketing landscape, and on that basis does not measure the fairness which truly is important in such an economy. The paper puts forward the concept of Fairness Quality (FAIRQUAL), which includes as well as extends on existing thinking behind relationship building, experience creation and other types of customer management practices that are believed to predict consumer intentions. It is proposed that a fairness quality measure will aid marketers in this challenging landscape and economy.

When rules and principles are not enough: insiders’ views and narratives on the global financial crisis

Much has been written about Wall Street and the global financial crisis (GFC). From a fraudulent derivatives market to a contestable culture of banking bonuses, culpability has been examined within the frames of American praxis, namely that of American exceptionalism. This study begins with an exploratory analysis of non-US voices concerning the nature of the causes of the GFC. The analysis provides glimpses of the globalized extent of assumptions shared, but not debated within the globalization convergence of financial markets as the neo-liberal project. Practical and paradigmatic tensions are revealed in the capture of a London-based set of views articulated by senior financial executives of financial service organizations, the outcomes of which are not overly optimistic for any significant change in praxis within the immediate future.

Concessionary nature of public-private partnerships in Russia and Kazakhstan: a critical review

This article provides a critical overview of Public-Private Partnerships (PPPs) in Russia and Kazakhstan and examines the rationale underpinning such partnerships. The analysis discusses the reasons why governments in Russia and Kazakhstan focus principally on concessions as a form of PPP and goes on to provide a critical assessment of the key approaches and situational factors relating to concessions in these two countries. The article finds that external globalization impulses pressed Russia and Kazakhstan to align their policies and institutions with western orthodoxy and perceived international best practice. An ever-increasing emphasis on use of PPPs has been a key feature of this alignment. However, the governments of Russia and Kazakhstan have increasingly resorted to concessions as progress with the development and implementation of Western style PPP models has stalled. This article concludes that the governments of Russia and Kazakhstan have demonstrated an overly optimistic approach to PPP and as a result may have substantially understated their overall concessional risks and costs. Features of Russian and Kazakhstani PPP arrangements such as ambiguity in output specification and extensive reliance on government subsidies, combined with lack of expertise of private partners, may significantly decrease concession benefits.

Towards (more) integrity in academia: transcending neo-liberal assumption of research and knowledge creation and the “rules” supressing academic freedom

European researchers across heterogeneous disciplines voice concerns and argue for new paths towards a brighter future regarding scientific and knowledge creation and communication. Recently, in biological and natural sciences concerns have been expressed that major threats are intentionally ignored. These threats are challenging Europe’s future sustainability towards creating knowledge that effectively deals with emerging social, environmental, health, and economic problems of a planetary scope. Within social science circles however, the root cause regarding the above challenges, have been linked with macro level forces of neo-liberal ways of valuing and relevant rules in academia and beyond which we take for granted. These concerns raised by heterogeneous scholars in natural and the applied social sciences concern the ethics of today’s research and academic integrity. Applying Bourdieu’s sociology may not allow an optimistic lens if change is possible. Rather than attributing the replication of neo-liberal habitus in intentional agent and institutional choices, Bourdieu’s work raises the importance of thoughtlessly internalised habits in human and social action. Accordingly, most action within a given paradigm (in this case, neo-liberalism) is understood as habituated, i.e. unconsciously reproducing external social fields, even ill-defined ways of valuing. This essay analyses these and how they may help critically analyse the current habitus surrounding research and knowledge production, evaluation, and communication and related aspects of academic freedom. Although it is acknowledged that transformation is not easy, the essay presents arguments and recent theory paths to suggest that change nevertheless may be a realistic hope once certain action logics are encouraged.

Investigation of the accuracy of historical irradiance products and interannual variability of solar irradiance using Met Office ground data

Met Office station data from 1980 to 2012 has been used to characterise the interannual variability of incident solar irradiance across the UK. The same data are used to evaluate four popular historical irradiance products to determine which are most suitable for use by the UK PV industry for site selection and system design. The study confirmed previous findings that interannual variability is typically 3–6% and weighted average probability of a particular percentage deviation from the mean at an average site in the UK was calculated. This weighted average showed that fewer than 2% of site-years could be expected to fall below 90% of the long-term site mean. The historical irradiance products were compared against Met Office station data from the input years of each product. This investigation has found that all products perform well. No products have a strong spatial trend. Meteonorm 7 is most conservative (MBE = −2.5%), CMSAF is most optimistic (MBE = +3.4%) and an average of all four products performs better than any one individual product (MBE = 0.3%)