Determinants of reelection in Portuguese municipal elections

This Work Project investigates the determinants of reelection using data on the 278 Portuguese mainland municipalities for the period 1976-2009. We implement a logit fixed effect model to control for the municipalities’ unobserved characteristics that remain constant over time. Political variables, such as the vote share of the incumbent’s party in previous election, the number of mayor’s consecutive mandates and abstention rate, are found to be relevant in explaining incumbent’s reelection. Moreover, as to the mayor’s individual characteristics, age and education contribute to explain reelection prospects. We also provide weak evidence that a higher degree of fiscal autonomy increases political turnover and that the good economic prospects of the municipality positively affect reelection. Finally, the residents’ level of education and the size of the municipal population have an explanatory power on mayor’s reelection. We perform several robustness checks to confirm these results.

Correcting the fixed-effect estimator for endogenous switching

In this paper, we propose a two-step estimator for panel data models in which a binary covariate is endogenous. In the first stage, a random-effects probit model is estimated, having the endogenous variable as the left-hand side variable. Correction terms are then constructed and included in the main regression.

A Fixed Order Model Matching Approach for the Design of Robust Power System Oscillation Damper

This book focuses on how evolutionary computing techniques benefit engineering research and development tasks by converting practical problems of growing complexities into simple formulations, thus largely reducing development efforts. This book begins with an overview of the optimization theory and modern evolutionary computing techniques, and goes on to cover specific applications of evolutionary computing to power system optimization and control problems.

Credit default swap (CDS) prediction model & trading strategy

This project focuses on the study of different explanatory models for the behavior of CDS security, such as Fixed-Effect Model, GLS Random-Effect Model, Pooled OLS and Quantile Regression Model. After determining the best fitness model, trading strategies with long and short positions in CDS have been developed. Due to some specifications of CDS, I conclude that the quantile regression is the most efficient model to estimate the data. The P&L and Sharpe Ratio of the strategy are analyzed using a backtesting analogy, where I conclude that, mainly for non-financial companies, the model allows traders to take advantage of and profit from arbitrages.

A Multilevel Model with Time Series Components for the Analysis of Tribal Art Prices

In the present work we perform an econometric analysis of the Tribal art market. To this aim, we use a unique and original database that includes information on Tribal art market auctions worldwide from 1998 to 2011. In Literature, art prices are modelled through the hedonic regression model, a classic fixed-effect model. The main drawback of the hedonic approach is the large number of parameters, since, in general, art data include many categorical variables. In this work, we propose a multilevel model for the analysis of Tribal art prices that takes into account the influence of time on artwork prices. In fact, it is natural to assume that time exerts an influence over the price dynamics in various ways. Nevertheless, since the set of objects change at every auction date, we do not have repeated measurements of the same items over time. Hence, the dataset does not constitute a proper panel; rather, it has a two-level structure in that items, level-1 units, are grouped in time points, level-2 units. The main theoretical contribution is the extension of classical multilevel models to cope with the case described above. In particular, we introduce a model with time dependent random effects at the second level. We propose a novel specification of the model, derive the maximum likelihood estimators and implement them through the E-M algorithm. We test the finite sample properties of the estimators and the validity of the own-written R-code by means of a simulation study. Finally, we show that the new model improves considerably the fit of the Tribal art data with respect to both the hedonic regression model and the classic multilevel model.

Supplementary tests of Masonboro Inlet fixed-bed model : hydraulic model investigation /

"General investigation of tidal inlets; a program of research conducted jointly by U.S. Army Coastal Engineering Research Center, Fort Belvoir, Virginia [and] U.S. Army Engineer Waterways Experiment Station, Vicksburg, Mississippi."

Statnote 30 : The one-way analysis of variance (ANOVA):fixed effects model

In Statnote 9, we described a one-way analysis of variance (ANOVA) ‘random effects’ model in which the objective was to estimate the degree of variation of a particular measurement and to compare different sources of variation in space and time. The illustrative scenario involved the role of computer keyboards in a University communal computer laboratory as a possible source of microbial contamination of the hands. The study estimated the aerobic colony count of ten selected keyboards with samples taken from two keys per keyboard determined at 9am and 5pm. This type of design is often referred to as a ‘nested’ or ‘hierarchical’ design and the ANOVA estimated the degree of variation: (1) between keyboards, (2) between keys within a keyboard, and (3) between sample times within a key. An alternative to this design is a 'fixed effects' model in which the objective is not to measure sources of variation per se but to estimate differences between specific groups or treatments, which are regarded as 'fixed' or discrete effects. This statnote describes two scenarios utilizing this type of analysis: (1) measuring the degree of bacterial contamination on 2p coins collected from three types of business property, viz., a butcher’s shop, a sandwich shop, and a newsagent and (2) the effectiveness of drugs in the treatment of a fungal eye infection.

Determinants of China’s regional innovation capacity

This paper investigates the determinants of China’s regional innovation capacity (RIC) and variations in these determinants between different types of regions. Based on the framework of national innovation capacity (NIC) and research on innovation system, this paper develops a framework of RIC in the Chinese context. Using panel data from 1991 to 2009, clustering analysis is first employed to classify regions according to their innovation development path. Panel data regressions with fixed effect model are conducted to explore the determinants of RIC and how these vary across the different regional clusters. We find that the 30 regions can be clustered into three groups, and there are considerable differences in the drivers of RIC between these different regional groups.

Postoperative chemotherapy for non-small cell lung cancer : a systematic review and meta-analysis

Background Postoperative chemotherapy is currently not recommended for resected non-small cell lung cancer in many countries and centers. Recently, results of several large randomized clinical trials were reported with conflicting evidence. Accordingly, we sought to determine whether postoperative chemotherapy is associated with improved survival compared with that after surgical intervention alone. Methods Randomized clinical trials with cisplatin- or uracil plus ftorafur-containing regimens were included and evaluated separately. A systematic review that included randomized clinical trials performed before 1995 was identified and found to be of adequate quality. Further randomized controlled trials were identified by searching MEDLINE, EMBASE, and the Cochrane Controlled Trials Register from 1995 through 2004. In addition, the reference lists of articles and conference abstracts were searched. The logarithm of the hazard ratio and its standard error were calculated, and a fixed-effect model was used to combine the estimates. Results There were 7200 patients enrolled in 19 trials included in the analyses. An overall estimate of 13% relative reduction in mortality (95% confidence interval, 7%-19%) was found. There was 11% relative reduction in mortality associated with postoperative cisplatin (95% confidence interval, 4%-18%; P = .004) and 17% associated with uracil plus ftorafur (95% confidence interval, 5%-27%; P = .006) compared with that after surgical intervention alone. This means that there would be an additional survivor at 5 years for 25 patients treated with cisplatin or for 30 patients treated with uracil plus ftorafur. Conclusions Postoperative chemotherapy is associated with improved survival compared with that after surgical intervention alone. Selected patients with completely resected non-small cell lung cancer should be offered chemotherapy. Copyright © 2004 by The American Association for Thoracic Surgery.

Family-based programmes for preventing smoking by children and adolescents (Review)

Background There is evidence that family and friends influence children's decisions to smoke. Objectives To assess the effectiveness of interventions to help families stop children starting smoking. Search methods We searched 14 electronic bibliographic databases, including the Cochrane Tobacco Addiction Group specialized register, MEDLINE, EMBASE, PsycINFO, CINAHL unpublished material, and key articles' reference lists. We performed free-text internet searches and targeted searches of appropriate websites, and hand-searched key journals not available electronically. We consulted authors and experts in the field. The most recent search was 3 April 2014. There were no date or language limitations. Selection criteria Randomised controlled trials (RCTs) of interventions with children (aged 5-12) or adolescents (aged 13-18) and families to deter tobacco use. The primary outcome was the effect of the intervention on the smoking status of children who reported no use of tobacco at baseline. Included trials had to report outcomes measured at least six months from the start of the intervention. Data collection and analysis We reviewed all potentially relevant citations and retrieved the full text to determine whether the study was an RCT and matched our inclusion criteria. Two authors independently extracted study data for each RCT and assessed them for risk of bias. We pooled risk ratios using a Mantel-Haenszel fixed effect model. Main results Twenty-seven RCTs were included. The interventions were very heterogeneous in the components of the family intervention, the other risk behaviours targeted alongside tobacco, the age of children at baseline and the length of follow-up. Two interventions were tested by two RCTs, one was tested by three RCTs and the remaining 20 distinct interventions were tested only by one RCT. Twenty-three interventions were tested in the USA, two in Europe, one in Australia and one in India. The control conditions fell into two main groups: no intervention or usual care; or school-based interventions provided to all participants. These two groups of studies were considered separately. Most studies had a judgement of 'unclear' for at least one risk of bias criteria, so the quality of evidence was downgraded to moderate. Although there was heterogeneity between studies there was little evidence of statistical heterogeneity in the results. We were unable to extract data from all studies in a format that allowed inclusion in a meta-analysis. There was moderate quality evidence family-based interventions had a positive impact on preventing smoking when compared to a no intervention control. Nine studies (4810 participants) reporting smoking uptake amongst baseline non-smokers could be pooled, but eight studies with about 5000 participants could not be pooled because of insufficient data. The pooled estimate detected a significant reduction in smoking behaviour in the intervention arms (risk ratio [RR] 0.76, 95% confidence interval [CI] 0.68 to 0.84). Most of these studies used intensive interventions. Estimates for the medium and low intensity subgroups were similar but confidence intervals were wide. Two studies in which some of the 4487 participants already had smoking experience at baseline did not detect evidence of effect (RR 1.04, 95% CI 0.93 to 1.17). Eight RCTs compared a combined family plus school intervention to a school intervention only. Of the three studies with data, two RCTS with outcomes for 2301 baseline never smokers detected evidence of an effect (RR 0.85, 95% CI 0.75 to 0.96) and one study with data for 1096 participants not restricted to never users at baseline also detected a benefit (RR 0.60, 95% CI 0.38 to 0.94). The other five studies with about 18,500 participants did not report data in a format allowing meta-analysis. One RCT also compared a family intervention to a school 'good behaviour' intervention and did not detect a difference between the two types of programme (RR 1.05, 95% CI 0.80 to 1.38, n = 388). No studies identified any adverse effects of intervention. Authors' conclusions There is moderate quality evidence to suggest that family-based interventions can have a positive effect on preventing children and adolescents from starting to smoke. There were more studies of high intensity programmes compared to a control group receiving no intervention, than there were for other compairsons. The evidence is therefore strongest for high intensity programmes used independently of school interventions. Programmes typically addressed family functioning, and were introduced when children were between 11 and 14 years old. Based on this moderate quality evidence a family intervention might reduce uptake or experimentation with smoking by between 16 and 32%. However, these findings should be interpreted cautiously because effect estimates could not include data from all studies. Our interpretation is that the common feature of the effective high intensity interventions was encouraging authoritative parenting (which is usually defined as showing strong interest in and care for the adolescent, often with rule setting). This is different from authoritarian parenting (do as I say) or neglectful or unsupervised parenting.

Combined pharmacotherapy and psychological therapies for post traumatic stress disorder (PTSD)

BACKGROUND PTSD is an anxiety disorder related to exposure to a severe psychological trauma. Symptoms include re-experiencing the event, avoidance and arousal as well as distress and impairment resulting from these symptoms.Guidelines suggest a combination of both psychological therapy and pharmacotherapy may enhance treatment response, especially in those with more severe PTSD or in those who have not responded to either intervention alone. OBJECTIVES To assess whether the combination of psychological therapy and pharmacotherapy provides a more efficacious treatment for PTSD than either of these interventions delivered separately. SEARCH STRATEGY Searches were conducted on the trial registers kept by the CCDAN group (CCDANCTR-Studies and CCDANCTR-References) to June 2010. The reference sections of included studies and several conference abstracts were also scanned. SELECTION CRITERIA Patients of any age or gender, with chronic or recent onset PTSD arising from any type of event relevant to the diagnostic criteria were included. A combination of any psychological therapy and pharmacotherapy was included and compared to wait list, placebo, standard treatment or either intervention alone. The primary outcome was change in total PTSD symptom severity. Other outcomes included changes in functioning, depression and anxiety symptoms, suicide attempts, substance use, withdrawal and cost. DATA COLLECTION AND ANALYSIS Two or three review authors independently selected trials, assessed their 'risk of bias' and extracted trial and outcome data. We used a fixed-effect model for meta-analysis. The relative risk was used to summarise dichotomous outcomes and the mean difference and standardised mean difference were used to summarise continuous measures. MAIN RESULTS Four trials were eligible for inclusion, one of these trials (n =24) was on children and adolescents. All used an SSRI and prolonged exposure or a cognitive behavioural intervention. Two trials compared combination treatment with pharmacological treatment and two compared combination treatment with psychological treatment. Only two trials reported a total PTSD symptom score and these data could not be combined. There was no strong evidence to show if there were differences between the group receiving combined interventions compared to the group receiving psychological therapy (mean difference 2.44, 95% CI -2.87, 7.35 one study, n=65) or pharmacotherapy (mean difference -4.70, 95% CI -10.84 to 1.44; one study, n = 25). Trialists reported no significant differences between combination and single intervention groups in the other two studies. There were very little data reported for other outcomes, and in no case were significant differences reported. AUTHORS' CONCLUSIONS There is not enough evidence available to support or refute the effectiveness of combined psychological therapy and pharmacotherapy compared to either of these interventions alone. Further large randomised controlled trials are urgently required.