Bayesian estimation of inefficiency heterogeneity in stochastic frontier models

Estimation of the one sided error component in stochastic frontier models may erroneously attribute firm characteristics to inefficiency if heterogeneity is unaccounted for. However, unobserved inefficiency heterogeneity has been little explored. In this work, we propose to capture it through a random parameter which may affect the location, scale, or both parameters of a truncated normal inefficiency distribution using a Bayesian approach. Our findings using two real data sets, suggest that the inclusion of a random parameter in the inefficiency distribution is able to capture latent heterogeneity and can be used to validate the suitability of observed covariates to distinguish heterogeneity from inefficiency. Relevant effects are also found on separating and shrinking individual posterior efficiency distributions when heterogeneity affects the location and scale parameters of the one-sided error distribution, and consequently affecting the estimated mean efficiency scores and rankings. In particular, including heterogeneity simultaneously in both parameters of the inefficiency distribution in models that satisfy the scaling property leads to a decrease in the uncertainty around the mean scores and less overlapping of the posterior efficiency distributions, which provides both more reliable efficiency scores and rankings.     

Entrepreneurship persistence with and without personnel: The role of human capital and previous unemployment

By considering entrepreneurs who hire employees (employers) and entrepreneurs without personnel (own-account workers) as related but distinct entrepreneurship groups, this work analyses factors in entrepreneurship survival from a new perspective: we contrast the determinants of employers’ survival with those affecting own-account workers’ survival. Discrete choice models under competing risks frameworks are applied to data drawn from the European Community Household Panel for the EU-15 (EUROSTAT). Our results suggest that survival chances are markedly higher for employers than for own-account workers—especially when non-employment exits are considered. We also observe that high qualifications have positive and statistically significant effects on survival rates of employers, regardless of exit routes, while high qualifications have no significant effect on survival rates of own-account workers. Finally, we find that entering entrepreneurship from unemployment—the target group for entrepreneurship incentives—strongly increases the probability of re-entering unemployment for both entrepreneurship groups. Thus, entrepreneurship and higher education policies should be considered together to develop high quality entrepreneurial businesses.     

Exploring the role of gender in common-pool resource extraction: evidence from laboratory and field experiments in fisheries

There is active debate on gender issues in natural resource management. For example, it is proposed that women are more cooperative than men when dealing with natural resources decisions; however, few scientific studies have directly addressed this hypothesis. We provide evidence for a greater cooperative attitude in women compared to men in both college students and coastal fishing communities of Baja California, Mexico, by means of game theory experiments. In both laboratory and field experiments, women changed their behaviour towards lower extraction compared to men, when regulations, sanctions or social scolding were introduced in the games. These results suggest that raising the role of women in decision-making, along with an adequate institutional framework, may lead to a more sustainable use of natural resources.     

Stock-bond decoupling before and after the 2008 crisis

In this article, we analyse the co-movements of daily stock prices and government bond prices during the last 25 years, in major Western stock markets, extending previous results to take into account the impact of the current crisis. Our results confirm that bonds are viewed as instruments for improving portfolio diversification in periods of high volatility and falling stock market levels, which is when such diversification is most needed. The possibility of using government debt in portfolios as a means of hedging during times of financial crisis became especially apparent in the crises of 1997, 2001 and 2008. Nevertheless, during the current one, this diversification quality of bonds has disappeared in countries like Italy or Spain, which are also affected by sovereign debt issues.     

New Headings – Old Problems: The Evolution and Future of the EU Budget

Despite its political signifi cance the size of the European Union’s budget is rather modest: the expenditures make up less than one per cent of the EU’s Gross National Income. This article aims to examine the long-term problems linked to the budget. Critical analysis of characteristic features of the EU budget is particularly important, as we argue the Multiannual Financial Framework 2014-2020 maintains the “old” problems, and we suggest that a more comprehensive long-term reform is necessary. Under such circumstances, it is worthwhile to refl ect on the tasks, functions and structural problems of the budget and on how to use available resources in a more structured and effi cient way.     

Economic impact of contrast-induced acute kidney injury associated with invasive cardiology: role of iso-osmolar contrast media in Germany,Italy, Poland,and Spain

Objective:

Iso-osmolar Iodixanol is associated with a lower rate of contrast-induced acute kidney injury (CI-AKI) in patients at increased risk compared to low-osmolar contrast media (LOCM). The aim of this study was to assess the financial consequences of CI-AKI risk reduction in patients undergoing coronary angiography (CA) with or without percutaneous coronary intervention (PCI) in German, Italian, Polish and Spanish hospitals.

Methods:

This budget impact analysis (BIA) compared a scenario with iodixanol to a scenario without, where only LOCM were used, in patients at increased risk of CI-AKI over a 3-year horizon. A meta-analysis based on a systematic review observed a lower rate of CI-AKI with iodixanol compared to LOCM (Risk Reduction?=?0.46) in patients with underlying impaired renal function (serum creatinine ≥1.6?mg/dl and estimated glomerular filtration rate ≤50?ml/min/1.73 m²). Contrast media and CI-AKI hospitalization costs were included in the analysis and unit costs were obtained from published literature, official sources or, when available, from hospital data. In the absence of country-specific data, resource utilization for a CI-AKI hospitalization was obtained by interviews with local clinicians in each country. The percentage of patients who received iodixanol was assumed to increase over time.

Results:

Based on a percentage of patients at increased risk of CI-AKI equal to 20% in Germany, 24% in Italy, 23% in Poland and 10% in Spain, results showed that the introduction of iodixanol would bring a 3-years cumulative net percentage saving on the total hospital budget of 29%, 34%, 25%, and 33% in the four countries respectively.

Conclusion:

The results of the analysis for the four countries showed that iodixanol use in patients at increased risk of CI-AKI undergoing CA with or without PCI may bring considerable savings on the hospital’s budget, due to the associated reduction in CI-AKI incidence.     

What do we [not] know about technology entrepreneurship research?

This study aims to review what we do (and do not) know about technology entrepreneurship (TE) research to date. Based on a categorized bibliometric analysis resulting from a systematic review of 135 scientific articles published in refereed journals over the past 27 years (1986–2013), we identify the core domains of TE, its intellectual structure, the scientific journals with a major impact in this field of research, and the affiliation and collaboration networks within it. Specifically, through a detailed analysis of article co-citations within the TE area, this study provides co-citation networks of authors, journals, and their respective clusters, revealing their rankings in terms of contributions to the TE literature. This comprehensive analysis can be used to enhance our understanding of TE and support further research in this field.     

Political economy and the ‘modern view’ as reflected in the history of economic thought

This paper focuses on the transition from classical political economy to ‘modern’ economics, a central aspect of which is the ascent of the conception of ‘theory’ as a mere instrument of research. We analyse how this transitional phase was perceived and interpreted in representative, more or less contemporaneous histories of economic thought: those by Luigi Cossa in 1880, by John Kells Ingram in 1915 (originally published in 1888), and by Charles Gide and Charles Rist in 1915. Despite their differences, all authors share the same conception of the structure of scientific laws, as well as the view that economics must be separated from liberalism.