Innovation and the performance of Portuguese businesses: a ‘SURE’ approach

There is a general consensus that in a competitive business environment, firms’ performance will depend on their capacity to innovate. To clarifying how, when and to what extent innovation affects the market and financial performance of firms, the authors deploy seemingly unrelated regression equation model to examine innovation in over 500 Portuguese firms from 1998 to 2004. The results confirm, as theorists have frequently assumed, that innovation positively affects firms’ performance; but they also suggest that the reverse is true, a result that is less intuitively obvious, given the complexity of the innovation process and local, national and global competitive environments.

Removal of Cd(II), Zn(II) and Pb(II) from aqueous solutions by brown marine macro algae: kinetic modelling

Specific marine macro algae species abundant at the Portuguese coast (Laminaria hyperborea, Bifurcaria bifurcata, Sargassum muticum and Fucus spiralis) were shown to be effective for removing toxic metals (Cd(II), Zn(II) and Pb(II)) from aqueous solutions. The initial metal concentrations in solution were about 75–100 mg L−1. The observed biosorption capacities for cadmium, zinc and lead ions were in the ranges of 23.9–39.5, 18.6–32.0 and 32.3–50.4 mg g−1, respectively. Kinetic studies revealed that the metal uptake rate was rather fast, with 75% of the total amount occurring in the first 10 min for all algal species. Experimental data were well fitted by a pseudo-second order rate equation. The contribution of internal diffusion mechanism was significant only to the initial biosorption stage. Results indicate that all the studied macro algae species can provide an efficient and cost-effective technology for eliminating heavy metals from industrial effluents.

Análise das determinantes da e-lealdade no comércio eletrónico

Objetivo – O objetivo deste trabalho é analisar e medir os determinantes da e-lealdade de um cliente no comércio eletrónico em Portugal. Metodologia – Foi realizado um estudo quantitativo empírico confirmatório e explicativo, a partir da identificação de um modelo teórico, suportado pelo levantamento bibliográfico sobre variáveis latentes, suscetível de investigar as relações entre os determinantes da e-lealdade. Os dados foram recolhidos através de um instrumento de medida, disponível online, o qual, permitiu obter uma amostra válida de 394 respondentes. As hipóteses foram testadas através de um modelo de equações estruturais. Resultados e conclusões – Estudaram-se e comprovaram-se a maioria das relações previstas e hipóteses, nomeadamente, a relação positiva das várias dimensões da e-confiança, e-satisfação e da e-qualidade de serviço na e-lealdade. A e-satisfação e a e-qualidade de serviço apresentam, também, um contributo interessante para a e-confiança que os consumidores têm nos produtos/serviços online. Quanto à e-satisfação dos consumidores foi possível verificar que a mesma apresenta uma variação, de acordo com a e-qualidade de serviço e a e-confiança, por parte dos consumidores online. Foi cumprida a validade convergente e discriminante das escalas de medida e a boa qualidade psicométrica das variáveis. Estas evidenciaram bons níveis de correlação e capacidades preditivas. Limitações/implicações – Os resultados obtidos precisam ser analisados com toda a precaução, não podendo ser objeto de generalizações, face ao uso de uma amostra de conveniência. O facto de os inquiridos avaliarem um website que estão já familiarizados pode constituir uma outra limitação. A ausência de estudos nacionais homólogos teve algumas implicações na discussão dos resultados. Originalidade/valor – O principal contributo deste estudo é constituir o primeiro realizado em Portugal, à data, onde se investigou e estimou um modelo proposto sobre os determinantes e antecedentes da e-lealdade no comércio eletrónico.

Impact of oral health on health-related quality of life : A cross-sectional study

Background: Despite the consensus regarding the existence of a relationship between “impacts on oral health” and “health-related quality of life”, this relationship, considering the latent nature of these variables, is still poorly investigated. Thus, we performed this study in order to determine the magnitude of the impacts of oral health, demographic and symptom/clinical variables on the health-related quality of life in a Brazilian sample of dental patients. Methods: A total of 1,007 adult subjects enrolled in the School of Dentistry of São Paulo State University (UNESP) - Araraquara Campus for dentistry care between September/2012 and April/2013, participated. 72.4 % were female. The mean age was 45.7 (SD = 12.5) years. The Oral Health Impact Profile (OHIP-14) and the Short Form Health Survey (SF-36) were used. The demographic and symptom/clinical variables collected were gender, age, economic status, presence of pain and chronic disease. The impact of studied variables on health-related quality of life were evaluated with a structural equation model, considering the factor “Health” as the central construct. The fit of the model was first analyzed by the evaluation of the goodness of fit indices (χ 2 /df ≤ 2.0, CFI and TLI ≥ 0.90 and RMSEA < 0.10) and the evaluation of the variables’ impact over health-related quality of life was based on the statistical significance of causal paths (β), evaluated by z tests, for a significance level of 5 %. Results: We observed adequate fit of the model to the data (χ 2 /df = 3.55; CFI = 0.95; TLI = 0.94; RMSEA = 0.05). The impacts on oral health explained 28.0 % of the variability of the health-related quality of life construct, while the total variance explained of the model was 39.0 %. For the demographic and symptom/clinical variables, only age, presence of pain and chronic disease showed significant impacts (p < 0.05). Conclusion: The oral health, age, presence of pain and chronic disease of individuals had significant influence on health-related quality of life.

A gestão de recursos humanos nas pequenas e médias empresas em Portugal: Definição de um modelo de atuação

Tese de Doutoramento em Ciências Empresariais

Desenvolvimento de talentos no desporto : aspectos psicológicos

A presente investigação tem como principal objetivo compreender a relevância de diversos fatores sociodemográficos e psicossociais inerentes ao desenvolvimento do talento em contexto desportivo, numa perspectiva multidimensional. Procedeu-se a uma avaliação quantitativa de jogadores de futebol, integrados num clube de elite, com idades compreendidas entre os 13 e os 19 anos. No sentido de avaliar os construtos psicológicos considerados no presente estudo (motivação, perfecionismo, suporte parental, resiliencia, coping e compromisso) foram utilizados os seguintes questionários: Sport Motivation Scale - SMS (Pelletier et al., 1995); Multidimensional Perfectionism Scale – MPS (Frost, Marten, Lahart, & Rosenblate, 1990); Own Memories of Parental Rearing – EMBU (Perris, Jacobson, Lindstörm, Von Knorring, & Perris, 1980); Resilience Scale – RS (Wagnild & Young, 1993); Athletic Coping Skills – ACSI 28 (Smith, Schutz, Smoll, & Ptacek, 1995); e Elite Athlete Commitment Scale – EACS (Ramadas, Serpa, Rosado, Gouveia & Maroco, 2013). A significância da variável nível de prestação (elite/sub-elite; dispensados/retidos) sobre os diversos constructos psicológicos foi avaliada através da análise da covariância multivariada (MANCOVA), da análise de equações estruturais (CBSEM) e da técnica de míninos quadrados parciais (PLS). Os jogadores mais bem sucedidos (jogadores de elite e jogadores retidos) percecionaram maior suporte parental, demonstraram níveis mais elevados de compromisso, resiliência, autodeterminação, capacidade de adaptação e confronto, assim como um perfeccionismo ajustado. No que concerne às variáveis sociodemográficas, constatou-se que os jogadores retidos jogam predominantemente no segundo ano do respetivo grupo de idade e têm uma idade inferior aos jogadores dispensados. Os resultados obtidos poderão constituir um relevante suporte para futuros programas educacionais que incidam sobre temáticas relacionadas com os compromissos necessários à prossecução e manutenção de níveis de elite, estratégias de coping, gestão da rotina diária, e o papel dos pais no processo de formação do jovem desportista.

Envolvimento parental no desporto

O presente conjunto de investigações pretendeu estudar o envolvimento parental na competição desportiva de crianças e jovens. Baseado no modelo do envolvimento parental no desporto (Teques & Serpa, 2009), o estudo permitiu concretizar dois objectivos fundamentais. Primeiro, desenvolver um conjunto de escalas válidas e fidedignas para aceder aos constructos incluídos no modelo teórico. Segundo, testar as hipóteses fundamentadas na estrutura conceptual do modelo com o propósito de compreender (1) a razão porque os pais se envolvem no desporto dos filhos, (2) quais os comportamentos utilizados pelos pais durante o envolvimento, e (3) como é que o envolvimento influencia o contexto de realização do jovem atleta. No total, participaram voluntariamente 1620 pais e 1665 jovens atletas de vários desportos individuais e coletivos, com idades compreendidas entre os 9 e os 18 anos. A prossecução dos objectivos teve por base uma série de três estudos independentes. Os resultados do primeiro estudo sugerem que as crenças do papel parental, a auto-eficácia, a perceção das invocações oriundas do treinador e do jovem atleta, o tempo e energia disponíveis, e os conhecimentos e competências relacionam-se com as atividades de envolvimento dos pais. No segundo estudo, os resultados demonstraram que as perceções dos comportamentos parentais de encorajamento, reforço, instrução, e modelagem medeiam a relação entre os comportamentos reportados pelos pais e as variáveis psicológicas de auto-eficácia, auto-eficácia social, motivação intrínseca, e estratégias de autorregulação dos jovens. Os resultados do terceiro estudo indicam que as perceções dos comportamentos dos pais relacionam-se com a realização desportiva através dos efeitos de mediação da auto-eficácia, autoeficácia social e das estratégias de autorregulação. Implicações para a intervenção, limitações e direções futuras para a investigação são também discutidas.

Poor and Sick: Estimating the relationship between Household Income and Health

This study evaluates the effect of the individual‘s household income on their health at the later stages of working life. A structural equation model is utilised in order to derive a composite and continuous index of the latent health status from qualitative health status indicators. The endogenous relationship between health status and household income status is taken into account by using IV estimators. The findings reveal a significant effect of individual household income on health before and after endogeneity is taken into account and after a host of other factors which is known to influence health, including hereditary factors and the individual‘s locus of control. Importantly, it is also shown that the childhood socioeconomic position of the individual has long lasting effects on health as it appears to play a significant role in determining health during the later stages of working life.

Development and Consequences of Referendum Campaigns in Switzerland, 1981-1999

Since the early 1990s, new forms of referendum campaigns have emerged in the Swiss political arena. In this paper, we examine how referendum campaigns have transformed in Switzerland, focusing on a number of features: their intensity, duration and inclusiveness (i.e., the variety of actors involved). These features are assumed to change in the long run in response to societal changes and in the short run as a function of variations in elite support. We further argue that public knowledge of ballot issues depends on the characteristics of campaigns. To formally test our hypotheses, we draw on advertisement campaigns in six major Swiss newspapers in the four weeks preceding each ballot from 1981 to 1999 and develop a structural equation model. We indeed find that the duration of referendum campaigns has increased over time, while their inclusiveness has decreased. Most importantly, we find that pub­lic knowledge is strongly related to the characteristics of campaigns

Coherent forecasting of multiple-decrement life tables: a test using Japanese cause of death data

Planners in public and private institutions would like coherent forecasts of the components of age-specic mortality, such as causes of death. This has been di cult toachieve because the relative values of the forecast components often fail to behave ina way that is coherent with historical experience. In addition, when the group forecasts are combined the result is often incompatible with an all-groups forecast. It hasbeen shown that cause-specic mortality forecasts are pessimistic when compared withall-cause forecasts (Wilmoth, 1995). This paper abandons the conventional approachof using log mortality rates and forecasts the density of deaths in the life table. Sincethese values obey a unit sum constraint for both conventional single-decrement life tables (only one absorbing state) and multiple-decrement tables (more than one absorbingstate), they are intrinsically relative rather than absolute values across decrements aswell as ages. Using the methods of Compositional Data Analysis pioneered by Aitchison(1986), death densities are transformed into the real space so that the full range of multivariate statistics can be applied, then back-transformed to positive values so that theunit sum constraint is honoured. The structure of the best-known, single-decrementmortality-rate forecasting model, devised by Lee and Carter (1992), is expressed incompositional form and the results from the two models are compared. The compositional model is extended to a multiple-decrement form and used to forecast mortalityby cause of death for Japan

Adherence to and effectiveness of highly active antiretroviral treatment for HIV infection: assessing the bidirectional relationship.

BACKGROUND: It is well established that high adherence to HIV-infected patients on highly active antiretroviral treatment (HAART) is a major determinant of virological and immunologic success. Furthermore, psychosocial research has identified a wide range of adherence factors including patients' subjective beliefs about the effectiveness of HAART. Current statistical approaches, mainly based on the separate identification either of factors associated with treatment effectiveness or of those associated with adherence, fail to properly explore the true relationship between adherence and treatment effectiveness. Adherence behavior may be influenced not only by perceived benefits-which are usually the focus of related studies-but also by objective treatment benefits reflected in biological outcomes. METHODS: Our objective was to assess the bidirectional relationship between adherence and response to treatment among patients enrolled in the ANRS CO8 APROCO-COPILOTE study. We compared a conventional statistical approach based on the separate estimations of an adherence and an effectiveness equation to an econometric approach using a 2-equation simultaneous system based on the same 2 equations. RESULTS: Our results highlight a reciprocal relationship between adherence and treatment effectiveness. After controlling for endogeneity, adherence was positively associated with treatment effectiveness. Furthermore, CD4 count gain after baseline was found to have a positive significant effect on adherence at each observation period. This immunologic parameter was not significant when the adherence equation was estimated separately. In the 2-equation model, the covariances between disturbances of both equations were found to be significant, thus confirming the statistical appropriacy of studying adherence and treatment effectiveness jointly. CONCLUSIONS: Our results, which suggest that positive biological results arising as a result of high adherence levels, in turn reinforce continued adherence and strengthen the argument that patients who do not experience rapid improvement in their immunologic and clinical statuses after HAART initiation should be prioritized when developing adherence support interventions. Furthermore, they invalidate the hypothesis that HAART leads to "false reassurance" among HIV-infected patients.

Univariate versus multivariate modeling of panel data

Panel data can be arranged into a matrix in two ways, called 'long' and 'wide' formats (LFand WF). The two formats suggest two alternative model approaches for analyzing paneldata: (i) univariate regression with varying intercept; and (ii) multivariate regression withlatent variables (a particular case of structural equation model, SEM). The present papercompares the two approaches showing in which circumstances they yield equivalent?insome cases, even numerically equal?results. We show that the univariate approach givesresults equivalent to the multivariate approach when restrictions of time invariance (inthe paper, the TI assumption) are imposed on the parameters of the multivariate model.It is shown that the restrictions implicit in the univariate approach can be assessed bychi-square difference testing of two nested multivariate models. In addition, commontests encountered in the econometric analysis of panel data, such as the Hausman test, areshown to have an equivalent representation as chi-square difference tests. Commonalitiesand differences between the univariate and multivariate approaches are illustrated usingan empirical panel data set of firms' profitability as well as a simulated panel data.

Ydinvoimalan paineakun mallinnus

Tässä työssä on käytetty VTT:n ja Fortumin kehittämääAPROS simulaatio-ohjelmistoa vesi-ilma -täytteisen paineakun käyttäytymisen tutkimiseen. Tavoitteena oli tarkastella APROSin paineakkumallin käyttäytymistä alhaisessa lämpötilassa käyttäen 6-yhtälömallia sekä rakentaa vaihtoehtoiseksi laskentamenetelmäksi kaksi analyyttistä laskentamallia korvaamaan APROSin sisäinen laskenta. Kyseiset analyyttiset mallit ovat isentrooppinen ja isoterminen ja ne on rakennettu kokonaan käyttäen APROSin omia moduuleja. Työ sisältää APROSin version 5.06 sekä työn aikana kehitetyn kehitysversion vertailut eri alkulämpötiloista alkaneissa paisunnoissa, vertailun Pactelin purkaus¬kokeesta saadulla massavirralla sekä osion, jossa analyyttiset mallit on yhdistetty kokonaiseen Pactelin APROS-malliin. Myös purkauksen kulkeutumista primääripiirissä on tarkasteltu. Simulaatiot vahvistavat, että versiolla 5.06 on vaikeuksia paineen laskennassa, kun paisunnan alkulämpötila on alle 30 ºC. Kehitysversiossa painekäyttäytyminen on selvästi parantunut, mutta versio kärsii ongelmista, jotka liittyvät kaasun lämpötilan painumiseen APROSin sisäisten rajoitusten alapuolelleja tätä kautta ongelmiin materiaali¬ominaisuuksien ennustamisessa. Tämän johdosta APROSin kehitysversio päätyy erilaisiin tuloksiin myös tilanteissa, joissa alkuperäinen 5.06 ei kärsi alhaisen lämpötilan ongelmista. Analyyttisistä malleista isentrooppinen malli päätyy antamaan säännönmukaisesti muita malleja ja versioita alempia paineita. Isoterminen malli sen sijaan näyttää päätyvän version 5.06 kanssa melko samankaltaisiin tuloksiin. On kuitenkin muistettava, että kummatkin analyyttiset mallit olettavat kaasun olevan kuivaa ja jättävät massasiirron faasien välillä kokonaan huomiotta.

Peso problem anddevaluation expectations: Evidence from Latin America

Tämän tutkielman tavoitteena on tutkia peso-ongelmaa sekä devalvaatio-odotuksia seuraavissa Latinalaisen Amerikan maissa: Argentiina, Brasilia, Costa Rica, Uruguay ja Venezuela. Lisäksi tutkitaan, onko peso-ongelmalla mahdollista selittää korkojen epäsäännöllistä käyttäytymistä ennen todellisen devalvaation tapahtumista. Jotta näiden tutkiminen olisi mahdollista, lasketaan markkinoiden odotettu devalvaation todennäköisyys tutkittavissa maissa. Odotettu devalvaation todennäköisyys lasketaan aikavälillä tammikuusta 1996 joulukuuhun 2006 käyttäen kahta erilaista mallia. Korkoero-mallin mukaan maiden välisestä korkoerosta on mahdollista laskea markkinoiden devalvaatio-odotukset. Toiseksi, Probit-mallissa käytetään useita makrotaloudellisia tekijöitä selittävinä muuttujina laskettaessa odotettua devalvaation todennäköisyyttä. Lisäksi tutkitaan, miten yksittäisten makrotaloudellisten muuttujien kehitys vaikuttaa odotettuun devalvaation todennäköisyyteen. Empiiriset tulokset osoittavat, että tutkituissa Latinalaisen Amerikan maissa oli peso-ongelma aikavälillä tammikuusta 1996 joulukuuhun 2006. Korkoero-mallin tulosten mukaan peso-ongelma löytyi kaikista muista tutkituista maista lukuun ottamatta Argentiinaa. Vastaavasti Probit-mallin mukaan peso-ongelma löytyi kaikista tutkituista maista. Tulokset osoittavat myös, että korkojen epäsäännöllinen kehitys ennen varsinaista devalvaatiota on mahdollista selittää peso-ongelmalla. Probit-mallin tulokset osoittavat lisäksi, että makrotaloudellisten muuttujien kehityksellä ei ole mitään tiettyä kaavaa liittyen siihen, kuinka ne vaikuttavat markkinoiden devalvaatio-odotuksiin Latinalaisessa Amerikassa. Pikemmin vaikutukset näyttävät olevan maakohtaisia.

The Effect of Tax Revenue Budgeting Errors on Fiscal Balance : Evidence from Swiss cantons

This study is an empirical analysis of the impact of direct tax revenue budgeting errors on fiscal deficits. Using panel data from 26 Swiss cantons between 1980 and 2002, we estimate a single equation model on the fiscal balance, as well as a simultaneous equation model on revenue and expenditure. We use new data on budgeted and actual tax revenue to show that underestimating tax revenue significantly reduces fiscal deficits. Furthermore, we show that this effect is channeled through decreased expenditure. The effects of over and underestimation turn out to be symmetric.