The Log of Gravity at 15

Portuguese Economic Journal - We review the contribution of “The Log of Gravity” (Santos Silva and Tenreyro, Rev Econ Stat 88:641–658, 2006), summarize the main results in the...     

煤发热量含义及其相互关系

指出煤的发热量是一项重要指标。重点介绍不同燃烧状态,不同基准的发热量的含义及其相互关系。     

Accelerators as start-up infrastructure for entrepreneurial clusters

ABSTRACT

Infrastructure is commonly conceptualized as a set of facilities that play a critical role in facilitating activities by individuals and organizations. Conventionally, infrastructure is tightly linked to publicly funded projects that facilitate access to key resources and enable diverse activities. Within entrepreneurial clusters research, infrastructure includes universities, research institutions and telecommunication technologies that facilitate entrepreneurial activities. These capital-intensive investments seek to facilitate start-ups emergence by aiding access to markets and development of ideas. Accelerators facilitate the same activities and have only recently been conceptualized as start-up infrastructure. This study builds upon this research stream by elaborating on how accelerators can play this meaningful role at the cluster level. Specifically, and by relying on the analysis of empirical evidence from three distinct studies, we uncover how accelerators provide tangible and intangible dimensions of start-up infrastructure to form a positively reinforcing cycle of entrepreneurial activities. Additionally, our findings allow us to push further the idea that start-up infrastructure development can be an endogenous process involving multiple actors within the cluster. Our empirical findings and the theoretical insights derived from them have meaningful implications for the aforementioned literature, as well as start-up practitioners and policymakers linked to the funding of entrepreneurial clusters.     

Semi-analytical prices for lookback and barrier options under the Heston model

Decisions in Economics and Finance - Under the Heston stochastic volatility model, we derive semi-analytical formulas for the prices of path-dependent options with payoffs linked to the maximum or...     

Commodity Price Volatility and the Sources of Growth

This paper studies the impact of the growth and volatility of commodity terms of trade (CToT) on economic growth, total factor productivity, physical capital accumulation and human capital acquisition. We use the standard system generalized methods of moments (GMM) approach as well as the dynamic common correlated effects pooled mean group (CCEPMG) methodology for estimation to account for cross‐country heterogeneity, cross‐sectional dependence and feedback effects. Using both annual data for 1970–2007 and 5‐year non‐overlapping observations, we find that while CToT growth enhances real output per capita, CToT volatility exerts a negative impact on economic growth operating mainly through lower accumulation of physical and human capital. Productivity, however, is not affected by either the growth or the volatility of CToT. Our results also indicate that the negative growth effects of CToT volatility offset the positive impact of commodity booms. Therefore, we argue that volatility, rather than abundance per se, drives the ‘resource curse’ paradox. Copyright © 2014 John Wiley & Sons, Ltd.     

Using ad hoc measures for response styles: a cautionary note

This research note addresses the challenge of how to optimally measure acquiescence response style (ARS) and extreme response style (ERS). This is of crucial importance in assessing results from studies that have tried to identify antecedents of response styles (such as age, education level, national culture). Using survey data from the Netherlands, a comparison is made between the traditional method and a more recently proposed method of measuring ARS and ERS (i.e., the convergent validity across both methods is assessed). The traditional method is based on an ad hoc set of related items. The alternative method uses a set of randomly sampled items to optimize heterogeneity and representativeness of the items. It is found that the traditional method may lead to response style measures that are suboptimal for estimating levels of ARS and ERS as well as relations of ARS and ERS with other variables (like hypothesized antecedents). Recommendations on how to measure response styles are provided.     

Optimal prepayment and default rules for mortgage-backed securities

We study the optimal stopping problems embedded in a typical mortgage. Despite a possible non-rational behaviour of the typical borrower of a mortgage, such problems are worth to be solved for the lender to hedge against the prepayment risk, and because many mortgage-backed securities pricing models incorporate this suboptimality via a so-called prepayment function which can depend, at time t, on whether the prepayment is optimal or not. We state the prepayment problem in the context of the optimal stopping theory and present an algorithm to solve the problem via weak convergence of computationally simple trees. Numerical results in the case of the Vasicek model and of the CIR model are also presented. The procedure is extended to the case when both the prepayment as well as the default are possible: in this case, we present a new method of building two-dimensional computationally simple trees, and we apply it to the optimal stopping problem.     

The Visible Hand of corporate entrepreneurship in state-owned enterprises: a longitudinal study of the Spanish National Postal Operator

This study explores how the corporate entrepreneurship (CE) of state-owned enterprises (SOEs) evolves under varying conditions of state ownership and control, laws and norms, and competence in the market. For this purpose, we present a longitudinal case study focused on the Spanish postal operator Correos using qualitative archival data and interviews. Our results indicate that the willingness and capacity of an SOE to act entrepreneurially depends critically on its degree of autonomy from the state and on the extent to which its legal and market environments increase its dynamism, complexity, and hostility. We also show that the development of CE in an SOE may lead to improved service quality, operational efficiency, and business specialization; facilitate its market positioning; and foster its sustainability through the exploration and exploitation of strategic alliances that can increase its business scope.

     

POLICY MAKING FOR INDUSTRIAL COMPETITIVENESS IN PORTUGAL - Patterns of change in a traditional bureaucracy

In Portugal the EEC membership represented a major change in Portuguese Administration functioning. This article uses the new institutionalism approach and the concept of path-dependence to analyse the change in the functioning of a central directorate reponsible for industrial policy. It argues that despite the external pressures for change has altered the directorate operations, there are patterns of continuity which are path-dependent. The response to change shows institutional reproduction in traditional features which is partly due to the reluctance to change traditional methods and partly because of the routines, procedures and norms embedded in the culture.