Estimating demand for primary health care services

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

Corruption and Education: Empirical evidence from cross-country micro-data

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

Promoting Portuguese exports to Germany: A hand-on approach for the machinery and equipment sector

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Identifying the urban communities of New York City using bikeshare data from NYC citibike

This study identifies a measure of the cultural importance of an area within a city. It does so by making use of origindestination trip data and the bike stations of the bike share system in New York City as a proxy to study the city. Rarely is movement in the city studied at such a small scale. The change in strength of the similarity of movement between each station is studied. It is the first study to provide this measure of importance for every point in the system. This measure is then related to the characteristics which make for vibrant city communities, namely highly mixed land use types. It reveals that the spatial pattern of important areas remains constant over differing time periods. Communities are then characterised by the land uses surrounding these stations with high measures of importance. Finally it identifies the areas of global cultural importance alongside the areas of local importance to the city.

Attractiveness of European masters under Bologna constraints: The South American case

This paper studies strategies to attract students from outside Europe to European preexperience masters. We characterize the value added by such masters through interviews with key players at the universities and multinational recruiting corporations. We considered a strategy for segmenting international students in the US and extended it to the European market. We have analyzed data from international applications to Nova SBE as a proxy for applications in European institutions. Based on that analysis we conclude with recommendations to attract suitable candidates from outside Europe. In particular we also provided three different solutions to attract students from the southern hemisphere: we conclude that European institutions should (a) increase the spring semester intake, (b) provide bridging courses for some students, or (c) could place some accepted candidates in internships before starting classes.

The Portuguese contemporary art as an investment

In this paper we investigate what drives the prices of Portuguese contemporary art at auction and explore the potential of art as an asset. Based on a hedonic prices model we construct an Art Price Index as a proxy for the Portuguese contemporary art market over the period of 1994 to 2014. A performance analysis suggests that art underperforms the S&P500 but overperforms the Portuguese stock market and American Government bonds. However, It does it at the cost of higher risk. Results also show that art as low correlation with financial markets, evidencing some potential in risk mitigation when added to traditional equity portfolios.

Projeto de desenvolvimento do sistema de contas nacionais financeiras em Moçambique

As Contas Nacionais ocupam uma posição de destaque no conjunto de todas as estatísticas económicas produzidas por um determinado país ou região, pois o sistema no qual assenta a sua produção, estabelece um padrão internacionalmente aceite em termos de conceitos, definições, classificações e metodologias permitindo a comparabilidade entre as várias estatísticas produzidas ao nível nacional e internacional, assim como a adaptação a qualquer país e a harmonização entre os diferentes sistemas estatísticos. No seu cerne está a medição do nível de crescimento e desempenho de uma economia, assim como a determinação da capacidade (+) / necessidade (‐) de financiamento de uma economia A produção das contas nacionais baseia‐se no Sistema de Contas Nacionais das Nações Unidas, cujo objetivo é a medição do nível de atividade económica (produto interno bruto), através do registo dos fluxos e stocks gerados entre os agentes económicos de uma economia, e entre estes e o resto do mundo, com base em padrões e recomendações internacionalmente aceites. O presente trabalho apresenta uma proposta de modelo de produção das estatísticas de contas nacionais financeiras em Moçambique, com vista a completar o modelo atualmente existente que comporta apenas a produção das contas não financeiras. Os resultados apresentados pelo modelo estão organizados em matrizes que resumem as operações financeiras realizadas entre os agentes económicos, onde se cruzam os instrumentos financeiros com os diversos setores institucionais residentes e o resto do mundo enquanto intervenientes nas operações realizadas. Nesse sentido, são apresentados, (i) quadros de património que apresentam o stock de ativos financeiros e passivos existentes num dado momento, assim como o saldo que representa o património líquido, (ii) a matriz “quem a quem” que resume as operações em forma de matriz tridimensional, onde aparecem os instrumentos financeiros e as duas partes intervenientes na operação na qualidade de credor e devedor, e (iii) a matriz de variação de stocks que, para efeitos deste trabalho, é apresentado como proxy da matriz de transações em ativos financeiros e passivos realizados num determinado momento, assim como a poupança financeira.

Correlates of intergenerational mobility and political violence

This work project aims at exploring the role of intergenerational immobility in political violence. A cross-country macro-level analysis is done where no significant results are found. Additionally, an individual micro-level analysis is done where intergenerational mobility (measured through a proxy variable) has a negative significant effect in political violence

Under the veil of citations

Academics are often ranked on citation counts’, which is considered an adequate proxy for author's quality and reputation. This paper seeks to find what is behind a cited academic / a cited article. We constructed a rich dataset from Portuguese affiliated economists and use zero inflated negative binomial model. This procedure is appropriate for count outcomes, correcting for overdispersion and excess zeros. We also use a fixed effect poisson model to accomodate authors' unobserved heterogeneity. We analyze results in detail comparing with existing literature and making some theoretical considerations around.

Estimating demand for primary health care services

Primary health services exist with the purpose of providing basic health care to every person at a cost they can afford. But is it fully available to everyone? The objective of this work project is to estimate the demand for primary health care services having into account that in some regions the citizens are not using as much health care as they would like due to supply side constraints. Using the number of consultations as proxy for demand, and applying an econometric tool called switching regression, the demand for primary health care services will be estimated.

Modelo preditivo de insolvência no setor farmacêutico : aplicação à farmácia comunitária portuguesa

O setor farmacêutico apresenta um elevado grau de complexidade, dada a regulamentação a que está sujeito. Atualmente, um dos principais problemas deste setor prende-se com o acentuado aumento (142,6% entre dezembro de 2012 e julho de 2014) do número de farmácias insolventes, sendo impacto da crise económica e consequentes medidas regulamentares aplicadas com o Memorando de Entendimento da Troika. Dada a importância que as farmácias têm na dispensa do medicamento assim como o papel do farmacêutico no aconselhamento diário aos utentes, a redução do número de farmácias levanta problemas no acesso ao medicamento por parte da população. Assim, é necessário dotar as farmácias de ferramentas que lhes permitam gerir o seu negócio, criando bases sólidas de forma a terem uma maior capacidade de reagir em tempos de crise. Desta forma, o objetivo principal do trabalho é fornecer às farmácias uma dessas ferramentas, através da criação de um modelo preditivo de insolvência que permita estimar uma probabilidade de uma farmácia entrar em insolvência. Para o efeito, desenvolveu-se um modelo teórico, com base na revisão de literatura científica e na análise do setor farmacêutico em Portugal, que foi depois testado recorrendo a métodos de estimação com recurso ao modelo logit através do método da Máxima Verosimilhança. O modelo empírico foi estimado com dados de uma amostra de 97 farmácias, selecionadas a partir de uma base de dados da ANF. Esta amostra é composta por todas as farmácias insolventes e por uma seleção aleatória de farmácias solventes, para as quais foi possível utilizar informação proveniente do IES, mantendo a total confidencialidade, nomeadamente dados relativos às dimensões consideradas no modelo teórico: Autonomia Financeira, Endividamento, Gestão de Inventários, Gestão de Funcionários, Liquidez, Prazo Médio de Pagamentos do Estado, Prazo Médio Pagamentos a Fornecedores, Rendibilidade, Solvabilidade, Tesouraria, Dimensão e Localização. As dimensões referidas foram selecionadas após uma análise extensiva da bibliografia sobre esta temática. Estas dimensões foram incluídas na estimação através de variáveis proxy (com exceção da Tesouraria), para as quais foi também levada a cabo uma análise de sensibilidade. Depois de validados os pressupostos da estimação e de uma análise crítica sobre os resultados, foi possível selecionar um modelo em que mais de 90% das observações foram classificadas corretamente. O modelo preditivo selecionado inclui as variáveis proxy das dimensões: Autonomia Financeira, Prazo Médio Pagamentos a Fornecedores, Endividamento, Rendibilidade, Dimensão e Localização. Em testes posteriores, validou-se a capacidade preditiva do modelo com recurso a uma amostra de teste.

Integration of geometric consistency contributory factors in three-leg junctions collision prediction models of Portuguese two-lane national highways

This paper aims at developing a collision prediction model for three-leg junctions located in national roads (NR) in Northern Portugal. The focus is to identify factors that contribute for collision type crashes in those locations, mainly factors related to road geometric consistency, since literature is scarce on those, and to research the impact of three modeling methods: generalized estimating equations, random-effects negative binomial models and random-parameters negative binomial models, on the factors of those models. The database used included data published between 2008 and 2010 of 177 three-leg junctions. It was split in three groups of contributing factors which were tested sequentially for each of the adopted models: at first only traffic, then, traffic and the geometric characteristics of the junctions within their area of influence; and, lastly, factors which show the difference between the geometric characteristics of the segments boarding the junctionsâ area of influence and the segment included in that area were added. The choice of the best modeling technique was supported by the result of a cross validation made to ascertain the best model for the three sets of researched contributing factors. The models fitted with random-parameters negative binomial models had the best performance in the process. In the best models obtained for every modeling technique, the characteristics of the road environment, including proxy measures for the geometric consistency, along with traffic volume, contribute significantly to the number of collisions. Both the variables concerning junctions and the various national highway segments in their area of influence, as well as variations from those characteristics concerning roadway segments which border the already mentioned area of influence have proven their relevance and, therefore, there is a rightful need to incorporate the effect of geometric consistency in the three-leg junctions safety studies.

Interaction paradigms versus age-related user profiles: an evaluation on content selection

Novel input modalities such as touch, tangibles or gestures try to exploit human's innate skills rather than imposing new learning processes. However, despite the recent boom of different natural interaction paradigms, it hasn't been systematically evaluated how these interfaces influence a user's performance or whether each interface could be more or less appropriate when it comes to: 1) different age groups; and 2) different basic operations, as data selection, insertion or manipulation. This work presents the first step of an exploratory evaluation about whether or not the users' performance is indeed influenced by the different interfaces. The key point is to understand how different interaction paradigms affect specific target-audiences (children, adults and older adults) when dealing with a selection task. 60 participants took part in this study to assess how different interfaces may influence the interaction of specific groups of users with regard to their age. Four input modalities were used to perform a selection task and the methodology was based on usability testing (speed, accuracy and user preference). The study suggests a statistically significant difference between mean selection times for each group of users, and also raises new issues regarding the “old” mouse input versus the “new” input modalities.

Spectrum-based energy leak localization

Dissertação de Mestrado em Engenharia Informática

Differential top-antitop cross-section measurements as a function of observables constructed from final-state particles using pp collisions at s√=7 TeV in the ATLAS detector

Various differential cross-sections are measured in top-quark pair (tt¯) events produced in proton--proton collisions at a centre-of-mass energy of s√=7 TeV at the LHC with the ATLAS detector. These differential cross-sections are presented in a data set corresponding to an integrated luminosity of 4.6 fb−1. The differential cross-sections are presented in terms of kinematic variables of a top-quark proxy referred to as the pseudo-top-quark whose dependence on theoretical models is minimal. The pseudo-top-quark can be defined in terms of either reconstructed detector objects or stable particles in an analogous way. The measurements are performed on tt¯ events in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of them tagged as originating from a b-quark. The hadronic and leptonic pseudo-top-quarks are defined via the leptonic or hadronic decay mode of the W boson produced by the top-quark decay in events with a single charged lepton.The cross-section is measured as a function of the transverse momentum and rapidity of both the hadronic and leptonic pseudo-top-quark as well as the transverse momentum, rapidity and invariant mass of the pseudo-top-quark pair system. The measurements are corrected for detector effects and are presented within a kinematic range that closely matches the detector acceptance. Differential cross-section measurements of the pseudo-top-quark variables are compared with several Monte Carlo models that implement next-to-leading order or leading-order multi-leg matrix-element calculations.