Search results for "Frontier"

Finding socially responsible portfolios close to conventional ones

2015

Abstract An increasing number of investors are interested in sustainable, responsible and impact investment (SRI). However, there is a concern about the possible financial sacrifice associated to this kind of investments. The design of Decision Support Systems assisting socially responsible investors in their investment decisions can contribute to stimulate SRI. In this paper the financial content of a portfolio selection model is discussed in order to justify that it can be integrated into a Decision Support System designed for investors interested in socially responsible investment but initially reluctant to pay a financial cost in exchange for increasing the social responsibility of thei…

CONVERGENCE AND DIVERGENCE: A NEW APPROACH, NEW DATA, AND NEW RESULTS

2020

Recently, Penn World Tables include new data that enable calculation of total factor productivity in addition to output for a large set of countries. We use these new data to examine convergence and divergence across countries by applying a new approach, which differentiates between the dynamics of output and of productivity. Our empirical results lead to two main new contributions to the literature. The first is on the interpretation of “β-convergence” in “growth regressions.” It means that output per worker in each country converges to productivity but does not imply convergence across countries, since productivity tends to diverge from the global frontier. The second contribution is to t…

A naïve approach to speed up portfolio optimization problem using a multiobjective genetic algorithm

2012

a b s t r a c t Genetic algorithms (GAs) are appropriate when investors have the objective of obtaining mean-variance (VaR) efficient frontier as minimising VaR leads to non-convex and non-differential risk-return optimisation problems. However GAs are a time-consuming optimisation technique. In this paper, we propose to use a naive approach consisting of using samples split by quartile of risk to obtain complete efficient frontiers in a reasonable computation time. Our results show that using reduced problems which only consider a quartile of the assets allow us to explore the efficient frontier for a large range of risk values. In particular, the third quartile allows us to obtain efficie…

Excessive Focus on Risk? Non-performing Loans and Efficiency of Microfinance Institutions

2021

Cumulative innovation, open source, and distance to frontier

2020

We develop a multistage game in which firms do cumulative research and development (R&D) to complete a lengthy process, and we study whether firms patent intermediate results or release them in Open Source. A patent holder obtains a larger reward in the market, but since in equilibrium it forecloses R&D, it remains alone to complete the process and so pays a larger cost than an Open Source firm. We have Open Source equilibria when R&D is highly complementary, R&D costs are large, and firms are sufficiently different and far from the frontier. We identify two market failures, in the forms of free riding and coordination failure, and we discuss public intervention.

Graphical models for estimating network determinants of multi-destination trips in Sicily

2017

Abstract This paper proposes a two-step approach for analysing the main determinants of multi-destination trip behaviour. It is based on a combination of graphical models and of a multinomial logistic regression model; the aim is to analyse direct and indirect effects of a wide set of tourist- and trip-related characteristics on multi-destination trip behaviour. Empirical data have been derived from a frontier survey of approximately 4000 incoming tourists in Sicily (Italy) at the end of their trip. Results suggest that multi-destination trips depend directly on the length of stay, the number of previous visits and motivation for the trip, and only indirectly on the interview month, travel …

Assessing the productivity change of water companies in England and Wales: A dynamic metafrontier approach

2017

The assessment of productivity change and its drivers across water companies and over time is a powerful tool for both regulators and companies when setting water tariffs. Water and sewerage companies (WaSCs) and water only companies (WoCs) provide different services. Hence, their productivity change cannot directly be evaluated jointly. In this paper and for the first time, we provide a pioneering approach to assess and compare the dynamics of productivity change of WaSCs and WoCs. To achieve this, both the traditional Malmquist productivity index and the metafrontier Malmquist productivity index and its components are computed to assess the productivity change for a sample of English and …

Methodological frontier in operational analysis for roundabouts: a review

2016

Several studies and researches have shown that modern roundabouts are safe and effective as engineering countermeasures for traffic calming, and they are now widely used worldwide. The increasing use of roundabouts and, more recently, turbo and flower roundabouts, has induced a great variety of experiences in the field of intersection design, traffic safety, and capacity modeling. As for unsignalized intersections, which represent the starting point to extend knowledge about the operational analysis to roundabouts, the general situation in capacity estimation is still characterized by the discussion between gap acceptance models and empirical regression models. However, capacity modeling mu…

The Luenberger productivity indicator in the water industry: An empirical analysis for England and Wales

2014

Abstract We innovate in the field of water companies' performance with an application of the directional distance function and the Luenberger productivity indicator (LPI) to the assessment of water companies' productivity growth. The advantage of our approach is that it takes into account both input contractions and output expansions. The analysis covered 22 water companies from England and Wales using data over the period 2001–2008. To the best of our knowledge, there are no prior studies applying the Luenberger productivity indicator to the water industry in England and Wales or other countries. For the sake of comparison, the traditional Malmquist productivity index (MPI) was also estima…

Pollution and economic growth: a maximum likelihood estimation of environmental Kuznets curve

2011

As in Brock and Taylor (2011) in this paper we consider the importance of the relationship between the Environmental Kuznets Curve (EKC) Literature and the Economic Growth Theories. To address this issue we construct country production functions that directly incorporate CO2 emissions as input and estimate them using Stochastic Frontiers. This approach differs from that of Brock and Taylor (2011) but is similar to the one followed by Koop (1998). By introducing the environmental “bads” directly in the production function, we can analyse their contribution to total output growth. We highlight an important contribution of CO2 emissions to growth and find out that the EKC seems not to hold, at…