1,721,261 research outputs found
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Time-varying coefficients in the almost ideal demand system: An empirical appraisal
No full textThis paper provides a generalisation of the structural time series version of the Almost Ideal Demand System (AIDS) that allows for time-varying coefficients (TVC/AIDS) in the presence of cross-equation constraints. An empirical appraisal of the TVC/AIDS is made using a dynamic AIDS with trending intercept as the baseline model with a data set from the Italian Household Budget Survey (1986-2001). The assessment is based on four criteria: adherence to theoretical constraints, statistical diagnostics on residuals, forecasting performance and economic meaningfulness. No clear evidence is found for superior performance of the TVC/AIDS, apart from improved short-term forecasts
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Time patterns in UK demand for alcohol and tobacco: an application of the EM algorithm
No full textCapturing the pattern of structural change is a relevant task in applied demand analysis, as consumer preferences may vary significantly over time. Filtering and smoothing techniques have recently played an increasingly relevant role. A dynamic Almost Ideal Demand System with random walk parameters is estimated in order to detect modifications in consumer habits and preferences, as well as changes in the behavioural response to prices and income. Systemwise estimation, consistent with the underlying constraints from economic theory, is achieved through the EM algorithm. The proposed model is applied to UK aggregate consumption of alcohol and tobacco, using quarterly data from 1963 to 2003. Increased alcohol consumption is explained by a preference shift, addictive behaviour and a lower price elasticity. The dynamic and time-varying specification is consistent with the theoretical requirements imposed at each sample point. (c) 2005 Elsevier B.V. All rights reserved
Impact of Bovine Spongiform Encephalopathy on agribusiness in the United Kingdom: Results of an event study of equity prices
No full textThis article assesses the impact on agribusinesses of the United Kingdom Government’s announcement of a possible link between Bovine Spongiform Encephalopathy and human health. Three approaches are employed to derive benchmark models against which abnormal eturns are estimated, a simple market model, Scholes-Williams approach, and an autoregressive distributed lag model. Abnormal returns are estimated for single firms and for subsectors over an eight-day event window. The autoregressive distributed lag model performs best and indicates significant negative abnormal returns in the beef, pet food, animal feed, and dairy sectors and positive abnormal returns in the other meats sector
A cointegrated VECM demand system for meat in Italy
No full textThis article applies cointegration techniques to estimate a monthly demand system for meat in Italy. In contrast to existing studies where Engle and Granger's two step procedure and Triangular Vector Error Correction Model (TVECM) representations are usually exploited, it applies a cointegrated Vector Error Correction Model (VECM) where also prices and expenditure enter endogenously the system and the cointegration rank is not assumed to be known a priori but subject to inference. It highlights some of the advantages of using the VECM compared to the TVECM, including the possibility of testing the cointegration rank of the system and the (weak and strong) exogeneity of prices and expenditure within a well-specified statistical model. This may lead to remarkable improvements in the efficiency of parameters system estimates
Earthquake effects on tourism in Central Italy
No full textThis paper proposes an approach to economic assessment of the impact on tourist flows of the earthquake that hit the Umbria region in Central Italy on September 26, 1997. Local arrivals in Assisi fell drastically the month following the main shock, compared to the same month of the previous year. The event study methodology, frequently applied in finance, is employed to evaluate the statistical relevance of the shock over time and space. A further and straightforward application of the event study analysis assesses the substantial amount of loss between October 1997 and June 1998 due to the drop of tourism business. © 2001 Elsevier Science Ltd. rights reserved
RECORD OF ACARTIA (ACARTIURA) MARGALEFI (COPEPODA, CALANOIDA, ACARTIIDAE) FROM THE NORWEGIAN AND THE BLACK SEAA
No full textPriceless behaviours: Behavioural implications, unintended consequences and spillover effects of pricing policies
No full textIn this chapter, we review the evidence on how price policies can lead to unintended
negative or positive effects, with a focus on the behavioural explanation
of the underlying mechanisms and the potential interaction with choice architecture
actions
Effects of prophylactic lipofilling after radiotherapy compared to non-fat injected breasts: A randomized, objective study
No full textBackground: Patients who are suffering from invasive breast cancer may require post-mastectomy radiation therapy (PMRT). PMRT improves outcomes in breast cancer patients in terms of locoregional recurrence. Preliminary studies indicate that fat injections reduce post-radiation damage of soft tissue and implants. Objectives: The aim of this study was to demonstrate the safety and effectiveness of prophylactic fat injections on radiated implanted breasts. Methods: The authors randomly assigned 60 female patients to either Group A or B. Group A patients received 3 breast fat injections, according to Coleman's technique, after radiotherapy and before expander removal with definitive implant insertion. Group B patients underwent surgery without lipofilling. At each surgical operation, skin biopsies were performed in a specific breast area to evaluate adipose tissue thickness, and a statistical analysis of the thickness variations was performed with the Wilcoxon's sum test. Disability was assessed according to the Late Effects of Normal Tissues-Subjective Objective Management Analytic scale. Results: The study demonstrates a qualitative and quantitative improvement about tissues after fat injection. This is highlighted by the significant increase in thickness after lipofilling. Conclusions: The study, which is based on both clinical and histological findings and is supported by the comparison of a control group with a 1-year follow-up, demonstrates that fat injections reduce tissue radio damage, improving reconstructive surgery outcomes and quality of life
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