16 research outputs found
Non-renewable resource prices: Structural breaks and long term trends
In this paper we examine the time series properties of nine non-renewable resources. In particular we are concerned with understanding the relationship between the number of structural breaks in the data and the nature of the resource price path, i.e. is it stationary or a random walk. To undertake our analysis we employ a number of relevant econometric methods including Bai and Perron`s (1998) multiple structural break dating method. Our results indicate that these series are in many cases stationary and subject to a number of structural breaks. These results indicate that a deterministic model of resources prices may well be appropriate.structural change, non-renewable resources, breaks, resource depletion
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Pollination services in the UK: how important are honeybees?
Pollination services are known to provide substantial benefits to human populations and agriculture in particular. Although many species are known to provide pollination services, honeybees (Apis mellifera) are often assumed to provide the majority of these services to agriculture. Using data from a range of secondary sources, this study assesses the importance of insect pollinated crops at regional and national scales and investigates the capacity of honeybees to provide optimal pollination services to UK agriculture. The findings indicate that insect pollinated crops have become increasingly important in UK crop agriculture and, as of 2007, accounted for 20% of UK cropland and 19% of total farmgate crop value. Analysis of honeybee hive numbers indicates that current UK populations are only capable of supplying 34% of pollination service demands even under favourable assumptions, falling from 70% in 1984. In spite of this decline, insect pollinated crop yields have risen by an average of 54% since 1984, casting doubt on long held beliefs that honeybees provide the majority of pollination services. Future land use and crop production patterns may further increase the role of pollination services to UK agriculture, highlighting the importance of measures aimed at maintaining both wild and managed species
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Preferences for Mitigation of the Negative impacts of the Oil and Gas Industry in the Niger Delta Region of Nigeria
We examine Nigerian preferences for the mitigation of negative impacts associated with oil and gas production using a discrete choice experiment. Our data are estimated using a Bayesian "infinite mixtures" model, which given its flexibility can approximate an array of existing model specifications including the mixed logit and finite mixture specifications. The application of this model to our data suggest multimodality in the distributions describing respondents' willingness to pay to mitigate the negative impacts of oil and gas production. Individuals are willing to pay for mitigation of negative impacts, but are not necessarily willing to trade-off very large increases in unemployment or poverty to achieve these benefits
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Overcoming undesirable resilience in the global food system
The current configuration of our global food system is undermining many of the UN Sustainable Development Goals (UN SDGs), leading to calls for major food system reform and transformation. Concurrently, other science-policy and business initiatives call for a food system more resilient to economic and environmental shocks, for example by improving the economic resilience of current supply chains. Prioritisation of short-term security to a subset of vested interests, however, can undermine the resilience of longer-term beneficial outcomes for society. Here we advocate a more inclusive and farsighted approach focussing on the resilience of positive outcomes for the whole of society, i.e., capturing the aim to promote resilient delivery of multiple UN SDGs. A significant challenge is to prioritise suites of interventions that can effectively transform the global food system to deliver these goals. Here, we use a transdisciplinary lens to identify ‘lock-in’ mechanisms that span four key areas— knowledge-based, economic/regulatory, sociocultural and biophysical constraints –which will help avoid ineffective siloed solutions to food system reform. Furthermore, we show how emergent system dynamics need to be considered using a more holistic approach. We highlight the importance of well-coordinated actions on multiple leverage points during windows of opportunity for food system transformation
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Pollinator monitoring more than pays for itself
1. Resilient pollination services depend on sufficient abundance of pollinating insects over time. Currently, however, most knowledge about the status and trends of pollinators is based on changes in pollinator species richness and distribution only. 2. Systematic, long‐term monitoring of pollinators is urgently needed to provide baseline information on their status, to identify the drivers of declines and to inform suitable response measures. 3. Power analysis was used to determine the number of sites required to detect a 30% change in pollinator populations over 10 years. We then evaluated the full economic costs of implementing four national monitoring schemes in the UK: (a) professional pollinator monitoring, (b) professional pollination service monitoring, (c) volunteer collected pan traps and (d) volunteer focal floral observations. These costs were compared to (a) the costs of implementing separate, expert‐designed research and monitoring networks and (b) the economic benefits of pollination services threatened by pollinator loss. 4. Estimated scheme costs ranged from £6,159/year for a 75‐site volunteer focal flower observation scheme to £2.7 M/year for an 800‐site professional pollination service monitoring network. The estimated research costs saved using the site network as research infrastructure range from £1.46–4.17 M/year. The economic value of UK crop yield lost following a 30% decline in pollinators was estimated at ~£188 M/year. 5. Synthesis and applications. We evaluated the full costs of running pollinator monitoring schemes against the economic benefits to research and society they provide. The annual costs of monitoring are <0.02% of the economic value of pollination services that would be lost after a 30% decline in pollination services. Furthermore, by providing high‐quality scientific data, monitoring schemes would save at least £1.5 on data collection per £1 spent. Our findings demonstrate that long‐term systematic monitoring can be a cost‐effective tool for both answering key research questions and setting action points for policymakers. Careful consideration must be given to scheme design, the logistics of national‐scale implementation and resulting data quality when selecting the most appropriate combination of surveyors, methods and site networks to deliver a successful scheme
Retesting symmetry and homogeneity in a cointegrated demand system with bootstrapping: The case of meat demand in Greece
A small Almost Ideal Demand System is estimated for Greek meat consumption using the Johansen procedure in conjunction with parametric bootstrapping and Bartlett corrections. Asymptotic Wald and likelihood ratio tests broadly support the predicted number of cointegrating relationships but reject symmetry and homogeneity. Bootstrapping and Bartlett corrections give support to symmetry and homogeneity but give less support for the predicted number of cointegrating relationships. Copyright Springer-Verlag 2004Symmetry, homogeneity, cointegration, Johansen procedure, bootstrapping, Bartlett corrections,
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Testing for bubbles in agriculture commodity markets
We apply the recent generalized sup augmented Dickey-Fuller (GSADF) test for explosive bubbles (Phillips et al., 2012) to monthly time-series for food, beverages, agricultural raw material, cereals, dairy, meat, oils and sugar indices and a total of 28 agricultural commodities between 1980-2012. We found price bubbles occurred for 6 out of the 10 indices studied and for 6 out of the 28 commodities within food markets. Results from the tests can help implementing policies aimed at mitigating effects of future price bubbles to targeted food commodity markets that may require special attention
Testing for bubbles in agricultural commodity markets
Food price volatility spells have fuelled the debate about the reliability of world markets as a source of food. At the heart of this debate lies the question of whether food price spikes are generated by the forces of demand and supply, or by speculation. We test for 'bubble' behaviour ' movements in the prices that cannot be explained by market fundamentals ' by applying the generalized version of the supremum Augmented Dickey-Fuller to several food price indices and 28 agricultural commodity prices. Our findings suggest that few food commodities exhibited bubble behaviour during the 2008 food price episode, with the price surges of 2010 and 2011 being due to market fundamentals. These spells of explosive behaviour are, in general, short-lived. Other commodities, which are also traded in futures markets, appear to respond only to the forces of supply and demand. Market conditions, such as stagnant productivity growth and low carry-over stocks, tend to shape the effect of speculation on prices. In some markets, trade policies, such as export bans, also appear to be crucial in generating bubble behaviour in prices
Expenditure on different categories of meat in Greece: the influence of changing tastes
This paper employs a latent variable approach to isolate the effects of changing tastes on the share of total meat expenditure
on different categories of meat products in Greece during the period 1965-1995. We find that changes in the relative expenditure
on different categories of meat cannot be explained by changes in the relative prices of the different meat products and increased
expenditure alone. For pork products in particular, the increase in the share of expenditure has been greater than would be
expected as a result of the relative fall in their price. The increase can therefore be associated with changes in taste. This finding
is of general interest to those conducting empirical research into consumer behaviour both in economies where there have
been significant changes in patterns of food consumption, and where, as in the case of many less industrialised economies,
rapid structural changes in food consumption patterns are still to come. It is also of importance to policy makers in assessing
the effectiveness of advertising or promotional campaigns in influencing longer term changes in consumer preferences for
different products