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Intervention Analysis (intervention + analysis)
Selected AbstractsReturn and Volatility Dynamics in the Spot and Futures Markets in Australia: An Intervention Analysis in a Bivariate EGARCH-X FrameworkTHE JOURNAL OF FUTURES MARKETS, Issue 9 2001Ramaprasad Bhar This article provides evidence of linkages between the equity market and the index futures market in Australia, where the futures market has experienced a major structural event due to the futures contract respecification. A bivariate Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) model is developed that includes a cointegrating residual as an explanatory variable for both the conditional mean and the conditional variance. The conditional mean returns from both markets are influenced by the long-run equilibrium relationship, and these markets are informationally linked through the second moments. The crossmarket spillovers exhibit asymmetric behavior in that the volatility responses to past standardized innovations are different for market advances and market retreats. An intervention analysis shows that some of the parameters describing the return-generating process have shifted after the contract respecification by the futures exchange. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:833,850, 2001 [source] A dendro-ecological study of forest overstorey productivity following the invasion of the non-indigenous shrub Lonicera maackiiAPPLIED VEGETATION SCIENCE, Issue 1 2007K.M. Hartman Gleason & Cronquist (1991) for vascular plants Abstract Question: Will a non-indigenous, invasive, understorey shrub, such as Lonicera maackii (Amur honeysuckle) have an impact on the productivity of overstorey trees in hardwood forests? Location: Trees from 12 invaded and four non-invaded sites were sampled in hardwood forests of southwestern Ohio, US. Methods: Changes in radial and basal area tree growth in the ten years prior to L. maackii invasion vs. ten years after invasion were examined using dendrochronological techniques. Intervention analysis was used to detect growth changes 25 years prior to and 25 years following invasion, and estimates of load impacts for L. maackii population and biomass were also calculated. Results: We found that the rate of radial and basal area growth of overstorey trees was reduced significantly in eleven out of twelve invaded sites. Non-invaded sites did not exhibit this consistent pattern of reduced growth. For invaded vs. non-invaded sites, the mean basal area growth was reduced by 15.8%, and the overall rate of basal area growth was reduced by 53.1%. Intervention analysis revealed that the first significant growth reductions were 6.25 ± 1.24 (mean ± SE) years after invasion with the greatest frequency of negative growth changes occurring 20 years after invasion. In invaded stands, 41% of trees experienced negative growth changes. In terms of invasive load estimates per 1000 L. maackii individuals, radial tree growth was reduced by 0.56 mm.a,1, and basal area growth was reduced by 0.74 cm2.a,1, Given these findings, significant economic losses could occur in hardwood forests of Ohio. Conclusions: To our knowledge, this is the first study using dendrochronological techniques to investigate the impact of a non-indigenous, understorey plant on overstorey tree growth. Active management will likely be needed to maintain forest productivity in L. maackii impacted landscapes. [source] Incorporating Maintenance Effectiveness in the Estimation of Dynamic Infrastructure Performance ModelsCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 3 2008Chih-Yuan Chu Specifically, we consider state-space specifications of autoregressive moving averages with exogenous inputs models to develop deterioration and inspection models for infrastructure facilities, and intervention analysis to estimate transitory and permanent effects of maintenance, for example, performance jumps or deterioration rate changes. To illustrate the methodology, we analyze the effectiveness of an overlay on a flexible pavement section from the AASHO Road Test. The results show the effect of the overlay on improvements both on surface distress, that is, rutting and slope variance, as well as on the pavement's underlying serviceability. The results also provide evidence that the overlay changes the pavement's response to traffic, that is, the overlay causes a reduction in the rate at which traffic damages the pavement. [source] John Heron's six-category intervention analysis: towards understanding interpersonal relations and progressing the delivery of clinical supervision for mental health nursing in the United KingdomJOURNAL OF ADVANCED NURSING, Issue 2 2001Graham Sloan BSc DipN RMN RGN DipCogPsychotherapy John Heron's six-category intervention analysis: towards understanding interpersonal relations and progressing the delivery of clinical supervision for mental health nursing in the United Kingdom Aims.,This paper provides a critique of how Heron's six-category intervention analysis framework has been adopted by nursing in the United Kingdom (UK) as a theoretical framework in nursing research and model for clinical supervision. From this, its merits as an analytic framework and model for clinical supervision in nursing are discussed. Background.,Heron's six-category intervention analysis has been acknowledged as a means by which nursing could develop its therapeutic integrity. It has also been used as a theoretical framework in nursing research focusing on nurses' perceptions of their interpersonal style. More recently descriptions of this framework have been proposed as a structure for clinical supervision. However, its use as a theoretical framework to underpin research investigating the interpersonal skills of nurses and as a model of clinical supervision must firstly be scrutinized. Findings.,Returning to Heron's original description and comparing this with its current adoption in the UK, misconceptions of this framework can be identified. Its value as an analytic tool investigating interpersonal relations in nursing has still to be evaluated. Furthermore, nursing's emphasis on certain intervention categories has undermined the potential potency of this framework and its contribution as a model for clinical supervision in nursing. Conclusion.,We argue that Heron's six-category intervention analysis as a framework to investigate the interpersonal competence of nurses, particularly mental health nurses, requires investigation. This, in turn, would provide an opportunity to challenge the framework's theoretical standpoint. In addition to its value as an analytic tool, all six categories of Heron's framework have equal relevance to its contribution in nursing as a supervision model. [source] Predicting food safety losses in turkey processing and the economic incentives of hazard analysis and critical control point (HACCP) interventionAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 4 2006William E. Nganje Turkey is an important food commodity whose total value of U.S. production amounted to $2.72 billion in 2003. Empirical evidence suggests that among broilers, eggs, turkeys, and chickens, Salmonella contamination of ground turkey is highest at 49.9% prior to hazard analysis and critical control point (HACCP) implementation and 26.6% after HACCP implementation. Salmonella and other microbial outbreaks have greatly contributed to the large number of food recalls in the meat and poultry industry; therefore, processed turkey constitutes a prime commodity for HACCP intervention analysis. Value-at-risk provides a framework for assisting firm management to assess food safety risks in monetary terms, and to evaluate the economic incentives of control measures like HACCP. Results show that food safety losses as measured by downside risk significantly declined following HACCP implementation. Medium- and large-scale turkey processors are more likely to derive more benefit from implementing an augmented HACCP plan than a generic HACCP plan. [EconLit citations: C150, Q180] © 2006 Wiley Periodicals, Inc. Agribusiness 22: 475,489, 2006. [source] THE IMPACT OF CLEAN FUEL SPECIFICATIONS ON ADELAIDE RETAIL PETROL PRICES,AUSTRALIAN ECONOMIC PAPERS, Issue 1 2009ALISTAIR DAVEY In March 2001, the South Australian Government introduced a clean fuel policy which it claimed was designed to protect air quality. This paper quantifies the policy's impact on relative Adelaide retail prices for unleaded petrol through Box-Jenkins autoregressive integrated moving average methodology coupled with Box and Tiao intervention analysis. The analysis uses weekly price data spanning from January 2000 until the beginning of June 2002. It finds the clean fuel policy had a statistically significant impact on relative retail petrol prices, resulting in an increase of almost 1.9 cents per litre and, therefore, costing Adelaide motorists around an extra $15.8 million per annum. Based on claims that the quality of fuel produced by the local Adelaide refiner did not change in response to the implementation of the clean fuel policy, the paper concludes that the increase in relative retail petrol prices was most likely associated with the exercise of market power rather than an increase in refinery production costs. [source] Deregulation of wholesale petrol prices: what happened to capital city petrol prices?AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 1 2010Alistair Davey Wholesale petrol prices were deregulated in August 1998. This paper will quantify the effect associated with the deregulation of wholesale petrol prices on relative retail prices for unleaded petrol in Adelaide, Melbourne and Sydney. This is done through Box,Jenkins autoregressive integrated moving average methodology coupled with Box and Tiao intervention analysis. Weekly price data will be used for Adelaide, Melbourne, and Sydney. It finds that from the beginning of 1999, deregulation coincided with relatively lower retail petrol prices for all three cities. In the absence of any other possible alternative explanation for the simultaneous fall in relative retail petrol prices across all three cities, it is concluded that this change was most likely associated with deregulation. These results suggest that regulation of wholesale petrol prices were ineffectual in terms of constraining capital city retail petrol prices at the very least and may have actually contributed towards relatively higher retail petrol prices. This also suggests that future policy interventions designed to constrain prices in the downstream petroleum industry should be very carefully considered. [source] | ||||||||||