752 research outputs found
Evidence from panel unit root and cointegration tests that the Environmental Kuznets Curve does not exist
The Environmental Kuznets Curve (EKC) hypothesis â an inverted U-shape relation between various indicators of environmental degradation and income per capita â has become one of the âstylised factsâ of environmental and resource economics. This is despite considerable criticism on both theoretical and empirical grounds. Cointegration analysis can be used to test the validity of such stylised facts when the data involved contain stochastic trends. In the present paper, we use cointegration analysis to test the EKC hypothesis using a panel dataset of sulfur emissions and GDP data for 74 countries over a span of 31 years. We find that the data is stochastically trending in the time-series dimension. Given this, and interpreting the EKC as a long run equilibrium relationship, support for the hypothesis requires that an appropriate model cointegrates and that sulfur emissions are a concave function of income. Individual and panel cointegration tests cast doubt on the general applicability of the hypothesised relationship. Even when we find cointegration, many of the relationships for individual countries are not concave. The results show that the EKC is a problematic concept, at least in the case of sulfur emissions.Environmental Economics and Policy,
Peak Oil, Progressivism, and Josephus Daniels, 1913â21
Danielsâs time as Secretary of the Navy was activated by Progressivism and peak oil. To preserve the Naval Oil Reserve, Daniels ultimately resorted to seizing oil, always at a below-market price and sometimes without compensation at all. His campaign to save the Navy from both peak oil and the ostensible predations of âbig oilâ ended in fiascoâfuel-oil seizures led by armed Marines
Precursor Analysis for Offshore Oil and Gas Drilling: From Prescriptive to Risk-Informed Regulation
The Oil Spill Commissionâs chartered missionâto âdevelop options to guard against ⊠any oil spills associated with offshore drilling in the futureâ (National Commission 2010)âpresents a major challenge: how to reduce the risk of low-frequency oil spill events, and especially high-consequence events like the Deepwater Horizon accident, when historical experience contains few oil spills of material scale and none approaching the significance of the Deepwater Horizon. In this paper, we consider precursor analysis as an answer to this challenge, addressing first its development and use in nuclear reactor regulation and then its applicability to offshore oil and gas drilling. We find that the nature of offshore drilling risks, the operating information obtainable by the regulator, and the learning curve provided by 30 years of nuclear experience make precursor analysis a promising option available to the U.S. Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) to bring cost-effective, risk-informed oversight to bear on the threat of catastrophic oil spills.catastrophic oil spills, quantitative risk analysis, risk-informed regulation
The Environmental Kuznets Curve: Implications of Non-stationarity
In this paper, we apply time series techniques for panel data to the environmental Kuznets curve (EKC) model. Within the literature that estimates emissions-income relations in the EKC context, little attention has been paid to the time series properties of the data and in particular to whether the variables could be integrated time series. We estimate the EKC for sulphur emissions using a panel data set for 74 countries over 30 years. Using individual unit root tests, we find that both sulphur emissions and GDP per capita are integrated variables in the majority of countries. This result is confirmed by panel unit root tests that find that the panel series are integrated. Individual cointegration tests show that EKC relations in most countries do not cointegrate. Results of a number of panel cointegration statistics are mixed. Even if there is cointegration in the panel many of the individual EKC functions are U shaped or monotonic in income. There is no single cointegrating vector common to all countries. The results show that the EKC may be a problematic concept, as simple global EKC models are misspecified
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Participatory Integrated Climate Services for Agriculture (PICSA): field manual. A step-by-step guide to using PICSA with farmers
Smallholder farmers are key to food security in sub-Saharan Africa where two thirds of the population depend on small-scale, rain-fed farming as their main source of food and income. Critical farming and household decisions depend upon the weather, for example, how much rain falls, the length and start date of the rainfall season and the timing of dry spells. Such aspects of the weather vary considerably from year to year.
The Participatory Integrated Climate Services for Agriculture (PICSA) approach aims to facilitate farmers to make informed decisions based on accurate, location specific, climate and weather information; locally relevant crop, livestock and livelihood options; and with the use of participatory tools to aid their decision making.
Considering farming and livelihood options in the context of climate is crucial for making good decisions. A farmer in Matumba village in central Tanzania expressed this notion perfectly when he said, âWe should select crops that look like the climateâ.
The PISCA approach has been designed with field staff in mind, and aims to support you to do your job better by providing you with improved resources and information.
This field manual is a step by step guide to working though the PICSA approach with farmer groups. It is primarily for the use of facilitators (e.g. NGO and extension field staff who have received training in the use of the PICSA approach). The PICSA approach is divided into twelve steps to be carried out with groups of farmers. Due to the location specific nature of PICSA there are a number of preparatory activities that need to be completed before field staff are trained in the approach. The details of these activities can be found in the document âPreparing for PICSAâ on the PICSA website (http://www.walker-institute.ac.uk/research/PICSA)
EXTENDING GENSTAT CAPABILITY TO ANALYZE RAINFALL DATA USING MARKOV CHAIN MODEL
Rainfall is of critical importance for many people particularly those whose livelihoods are dependent on rain fed agriculture. Methods of analysis of daily rainfall records based on Markov chain models have been available for many years and their value is widely recognized. However they are rarely used because of the complexity of their analysis. This paper describes how these models are being made more accessible through a series of specially written procedures and menus in GenStat, a widely available statistics package
Extending genstat capability to analyze rainfall data using Markov chain model
Rainfall is of critical importance for many people particularly those whose livelihoods are dependent on rain fed agriculture. Methods of analysis of daily rainfall records based on Markov chain models have been available for many years and their value is widely recognized. However they are rarely used because of the complexity of their analysis. This paper describes how these models are being made more accessible through a series of specially written procedures and menus in GenStat, a widely available statistics package.Rainfall is of critical importance for many people particularly those whose livelihoods are dependent on rain fed agriculture. Methods of analysis of daily rainfall records based on Markov chain models have been available for many years and their value is widely recognized. However they are rarely used because of the complexity of their analysis. This paper describes how these models are being made more accessible through a series of specially written procedures and menus in GenStat, a widely available statistics package
Morphologies of Radio, X-Ray, and Mid-Infrared Selected AGN
We investigate the optical morphologies of candidate active galaxies
identified at radio, X-ray, and mid-infrared wavelengths. We use the Advanced
Camera for Surveys General Catalog (ACS-GC) to identify 372, 1360, and 1238 AGN
host galaxies from the VLA, XMM-Newton and Spitzer Space Telescope observations
of the COSMOS field, respectively. We investigate both quantitative (GALFIT)
and qualitative (visual) morphologies of these AGN host galaxies, split by
brightness in their selection band. We find that the radio-selected AGN are
most distinct, with a very low incidence of having unresolved optical
morphologies and a high incidence of being hosted by early-type galaxies. In
comparison to X-ray selected AGN, mid-IR selected AGN have a slightly higher
incidence of being hosted by disk galaxies. These morphological results conform
with the results of Hickox et al. 2009 who studied the colors and large-scale
clustering of AGN, and found a general association of radio-selected AGN with
``red sequence'' galaxies, mid-IR selected AGN with ``blue cloud'' galaxies,
and X-ray selected AGN straddling these samples in the ``green valley.'' In the
general scenario where AGN activity marks and regulates the transition from
late-type disk galaxies into massive elliptical galaxies, this work suggests
that the earlier stages are most evident as mid-IR selected AGNs. Mid-IR
emission is less susceptible to absorption than the relatively soft X-rays
probed by XMM-Newton, which are seen at later stages in the transition.
Radio-selected AGN are then typically associated with minor bursts of activity
in the most massive galaxies.Comment: 28 page
Climate change adaptation strategies in Sub-Saharan Africa: foundations for the future
Many institutions across sub-Saharan Africa (SSA) and many funding agencies that support
them are currently engaged in initiatives that are targeted towards adapting rainfed
agriculture to climate change. This does, however, present some very real and complex
research and policy challenges. Given to date the generally low impact of agricultural
research across SSA on improving the welfare of rainfed farmers under current climatic
conditions, a comprehensive strategy is required if the considerably more complex challenge
of adapting agriculture to future climate change is to bear fruit. In articulating such a
strategy, it is useful to consider the criteria by which current successful initiatives should be
judged
A cell lineage analysis of segmentation in the chick embryo
We have studied the lineage history of the progenitors of the somite mesoderm and of the neural tube in the chick embryo by injecting single cells with the fluorescent tracer, rhodamine-lysine-dextran. We find that, although single cells within the segmental plate give rise to discrete clones in the somites to which they contribute, neither the somites nor their component parts (sclerotome, dermatome, myotome or their rostral and caudal halves) are `compartments' in the sense defined in insects. Cells in the rostral two thirds or so of the segmental plate contribute only to somite tissue and divide about every 10 h, while those in the caudal portions of this structure contribute both to the somites and to intermediate and lateral plate mesoderm derivatives. In the neural tube, the descendants of individual prospective ventral horn cells remain together within the horn, with a cycle time of 10 h.
We have also investigated the role of the cell division cycle in the formation and subsequent development of somites. A single treatment of 2-day chick embryos with heat shock or a variety of drugs that affect the cell cycle all produce repeated anomalies in the pattern of somites and vertebrae that develop subsequent to the treatment. The interval between anomalies is 6-7 somites (or a multiple of this distance), which corresponds to 10 h. This interval is identical to that measured for the cell division cycle. Given that cell division synchrony is seen in the presomitic mesoderm, we suggest that the cell division cycle plays a role in somite formation.
Finally, we consider the mechanisms responsible for regionalization of derivatives of the somite, and conclude that it is likely that both cell interactions and cell lineage history are important in the determination of cell fates
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