21,157 research outputs found

    How Has the Portuguese Innovation Capability Evolved? Estimating a Time Series of the Stock of Technological Knowledge, 1960-2001

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    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

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    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

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    Consider a sequence of possibly random graphs GN=(VN,EN)G_N=(V_N, E_N), N1N\ge 1, whose vertices's have i.i.d. weights {WxN:xVN}\{W^N_x : x\in V_N\} with a distribution belonging to the basin of attraction of an α\alpha-stable law, 0<α<10<\alpha<1. Let XtNX^N_t, t0t \ge 0, be a continuous time simple random walk on GNG_N which waits a \emph{mean} WxNW^N_x exponential time at each vertex xx. Under considerably general hypotheses, we prove that in the ergodic time scale this trap model converges in an appropriate topology to a KK-process. We apply this result to a class of graphs which includes the hypercube, the dd-dimensional torus, d2d\ge 2, random dd-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

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    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

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    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

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    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

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    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, χ20~χ10 \chi_2^0\to \tilde \ell \,\ell \to \ell \,\ell\,\chi_1^0 decays, in combination with other observables, render feasible the reconstruction of the masses of the intermediate sleptons, and hence the study of ij\ell_i - \ell_j 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

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    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

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    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

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    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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