21,157 research outputs found
How Has the Portuguese Innovation Capability Evolved? Estimating a Time Series of the Stock of Technological Knowledge, 1960-2001
The importance of promoting innovation has been elevated up to a status of official standard since the Lisbon European Summit in 2000. Here research and development (R&D) was singled out as an essential element of the foundation on which innovation could be built. R&D has been a growing area of investigation namely at level of firms micro studies aimed at uncovering firms’ innovation capability. At the macro level, the relevance of R&D for countries’ innovation capability has been, in a dynamic perspective, more often presumed rather than effectively tested. This latter limitation is, to a large extent, explained by the paucity of aggregated continuous time series on innovation indicators specifically those based on R&D expenditures. This paper aims at filling this gap by providing an estimate of the Portuguese innovation capability over the two last four decades based on the accumulated R&D efforts. Such indicator, albeit preliminary, will desirably endorse new investigation on the Portuguese catching-up process and, in this way, might inform present and future public programs related to R&D policies in particular and innovation policies in general.Innovation; R&D expenditures; measurement, economic growth
An empirical analysis of structural models of corporate debt pricing
This paper tests empirically the performance of three structural models of corporate bond pricing, namely Merton (1974), Leland (1994) and Fan and Sundaresan (2000). While the first two models overestimate bond prices, the Fan and Sundaresan model reveals an extremely good performance. When considering the prediction of credit spreads, the three models under-estimate market spreads but, again, Fan and Sundaresan has a better performance. We find rating, maturity and asset volatility effects in the prediction power, as the models under-estimate less the spreads of riskier firms and of bonds with better rating quality and longer maturity. Moreover, our results reveal the existence of a new industry effect. Spread errors are systematically related to some bond- and firm-specific variables, as well as term structure variables.structural models, corporate debt valuation, empirical credit spreads
Universality of trap models in the ergodic time scale
Consider a sequence of possibly random graphs , ,
whose vertices's have i.i.d. weights with a distribution
belonging to the basin of attraction of an -stable law, .
Let , , be a continuous time simple random walk on which
waits a \emph{mean} exponential time at each vertex . Under
considerably general hypotheses, we prove that in the ergodic time scale this
trap model converges in an appropriate topology to a -process. We apply this
result to a class of graphs which includes the hypercube, the -dimensional
torus, , random -regular graphs and the largest component of
super-critical Erd\"os-R\'enyi random graphs
FDI, income inequality and poverty : a time series analysis of Portugal, 1973–2016
Using time series data for Portugal between 1973 and 2016, this paper examines to what extent, inward FDI contributes to income inequality and poverty in the long-run. It was found that increased flows of inward FDI are associated with a less unequal income distribution and lower poverty rates. The results further suggest that, in the Portuguese case there is mutual causality between inward FDI and poverty in the long run, i.e., FDI significantly reduces poverty, and lower levels of poverty lead to higher inward FDI flows. In the case of inequality, the evidence shows that FDI does not contribute to higher (or lower) income inequality. Instead, more unequal income distributions significantly and negatively impact on inward FDI in the long run. Finally, human capital emerged as a key determinant to mitigate income inequality and circumvent poverty, contributing, indirectly, to fostering additional FDI inflows. Such results call for integrated public policy interventions that emphasize social and institu- tional dimensions.info:eu-repo/semantics/publishedVersio
The innovative behaviour of tourism firms
Tourism is a growing and an extremely competitive sector. To be competitive, tourism firms need do innovate, responding to the more and more demanding tourist. Nonetheless, research on this field is limited and insufficient. In Portugal, the tourism sector is a highly strategic sector for the Portuguese economy, but there is no evidence on how Portuguese tourism firms innovate. This paper presents a thesis proposal with the aim to provide empirical evidence of the innovative behaviour of Portuguese tourism firm. Trough a direct survey on all the Portuguese tourism firms we intent to investigate firms’ innovativeness and their determinants and then compare the results with data from Danish and Spanish tourism firms. The literature on innovation in services and in tourism, in particular Sunbdo et al. (2007) taxonomy of tourism firms, provides us a guide to our investigation. It is also our aim to contribute with additional findings on the process of innovation in the tourism industry.Innovation, Tourism Industries, Portugal
Lepton masses and mixings in orbifold models with three Higgs families
We analyse the phenomenological viability of heterotic Z(3) orbifolds with
two Wilson lines, which naturally predict three supersymmetric families of
matter and Higgs fields. Given that these models can accommodate realistic
scenarios for the quark sector avoiding potentially dangerous flavour-changing
neutral currents, we now address the leptonic sector, finding that viable
orbifold configurations can in principle be obtained. In particular,it is
possible to accomodate present data on charged lepton masses, while avoiding
conflict with lepton flavour-violating decays. Concerning the generation of
neutrino masses and mixings, we find that Z(3) orbifolds offer several
interesting possibilities.Comment: 28 pages, 11 figures. References adde
Phenomenology of LFV at low-energies and at the LHC: strategies to probe the SUSY seesaw
We study the impact of a type-I SUSY seesaw concerning lepton flavour
violation (LFV) at low-energies and at the LHC. At the LHC, decays, in combination with other
observables, render feasible the reconstruction of the masses of the
intermediate sleptons, and hence the study of mass
differences. If interpreted as being due to the violation of lepton flavour,
high-energy observables, such as large slepton mass splittings and flavour
violating neutralino and slepton decays, are expected to be accompanied by
low-energy manifestations of LFV such as radiative and three-body lepton
decays. We discuss how to devise strategies based in the interplay of slepton
mass splittings as might be observed at the LHC and low-energy LFV observables
to derive important information on the underlying mechanism of LFV.Comment: 6 pages, 4 figures. To appear in the proceedings of the 11th
International Workshop on Tau Lepton Physics (TAU2010), Manchester, UK, 13-17
September 201
Lepton flavour violation: physics potential of a Linear Collider
We revisit the potential of a Linear Collider concerning the study of lepton
flavour violation, in view of new LHC bounds and of the (very) recent
developments in lepton physics. Working in the framework of a type I
supersymmetric seesaw, we evaluate the prospects of observing seesaw-induced
lepton flavour violating final states of the type e \mu + missing energy,
arising from e+ e- and e- e- collisions. In both cases we address the potential
background from standard model and supersymmetric charged currents. We also
explore the possibility of electron and positron beam polarisation. The
statistical significance of the signal, even in the absence of kinematical
and/or detector cuts, renders the observation of such flavour violating events
feasible over large regions of the parameter space. We further consider the
\mu-\mu- + E^T_miss final state in the e- e- beam option finding that, due to a
very suppressed background, this process turns out to be a truly clear probe of
a supersymmetric seesaw, assuming the latter to be the unique source of lepton
flavour violation.Comment: 30 pages, 48 figure
Potential of a Linear Collider for Lepton Flavour Violation studies in the SUSY seesaw
We study the potential of an e+- e- Linear Collider for charged lepton
flavour violation studies in a supersymmetric framework where neutrino masses
and mixings are explained by a type-I seesaw. Focusing on e-mu flavour
transitions, we evaluate the background from standard model and supersymmetric
charged currents to the e mu + missing E_T signal. We study the energy
dependence of both signal and background, and the effect of beam polarisation
in increasing the signal over background significance. Finally, we consider the
mu- mu- + missing E_T final state in e- e- collisions that, despite being
signal suppressed by requiring two e-mu flavour transitions, is found to be a
clear signature of charged lepton flavour violation due to a very reduced
standard model background.Comment: 8 pages, 5 figures. To appear in the proceedings of "DISCRETE 2012 -
3rd Symposium on Prospects in the Physics of Discrete Symmetries", Lisbon,
Portugal, 3-7 December 201
The importance of Intermediaries organizations in international R&D cooperation: an empirical multivariate study across Europe
Despite the large number of publications related to business cooperation in R&D and the wide perception of the importance of intermediary institutions in the R&D cooperation process, empirical studies on its role are scarce, scattered and fragmented. Moreover, the academic work developed in this area is basically of a theoretical nature, whereas the international perspective of R&D cooperation is seldom approached. Departing from a unique database that includes 473 R&D cooperation projects developed within the 6th Framework Programme, involving firms and intermediaries from all European Union countries, this paper gauges the determinants of the importance attached to Intermediaries, through a direct survey to the organizations involved. Based on an estimation of the multivariate model, this study demonstrates that the importance given to Intermediaries depends more on project features than on the characteristics of the participating organizations. In particular, the nationality of participating organizations and the promoter emerged with a strong explanatory power: ceteris paribus, projects with at least one participant from the United Kingdom tend to assign greater importance to intermediaries in international R&D cooperation. Unambiguously, results evidence that the innovating capacity of an organization emerges (both positively and significantly) associated with a greater importance attached to Intermediaries.R&D Cooperation; Intermediaries; International projects; Europe
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