A proposed configurable approach for recommendation systems via data mining techniques

This study presents a configurable approach for recommendations which determines the suitable recommendation method for each field based on the characteristics of its data, the method includes determining the suitable technique for selecting a representative sample of the provided data. Then selecting the suitable feature weighting measure to provide a correct weight for each feature based on its effect on the recommendations. Finally, selecting the suitable algorithm to provide the required recommendations. The proposed configurable approach could be applied on different domains. The experiments have revealed that the approach is able to provide recommendations with only 0.89 error rate percentage.     

What drives international equity correlations? Volatility or market direction?

We consider impulse response functions to study the impact of both return and volatility on the correlation between international equity markets. Using data on the US (as the reference country), Canada, the UK and France equity indices, empirical evidence shows that without taking into account the effect of return, there is an (asymmetric) effect of volatility on correlation. The volatility seems to have an impact on correlation especially during downturn periods. However, once we introduce the effect of return, the impact of volatility on correlation disappears. These observations suggest that, the relation between volatility and correlation is an association rather than a causality. The strong increase in the correlation is driven by the past of the return and the market direction rather than the volatility.     

Competition among stock exchanges for equity

We consider cross-border competition by stock exchanges for listings from firms that have controlling shareholders who have private benefits. We examine exchanges’ choices of their listing standards and firms’ choices of the exchanges where they cross-list their shares. We show that the share price compensates controlling shareholders for giving up some private benefits and enables firms with growth opportunities to obtain listings on exchanges with different listing standards. In particular, firms with high-growth opportunities tend to obtain listings on stock exchanges with high listing standards. We empirically examine these predictions and find that they are consistent with evidence.     

Incentive Regulation and The Cost Structure of The Local Telephone Exchange Network

This paper combines an engineering process model of the cost of local exchange telecommunications firms with an analytical model of optimal incentive regulation (with ex post cost observability), to study empirically the properties of the optimal regulatory mechanism. Relying on detailed properties of the cost function, we examine three issues: (i) the extent of natural monopoly when informational rents associated with regulation are taken into account; (ii) the extent of incentive correction, which expresses the divergence of pricing under the optimal mechanism from optimal pricing under complete information; (iii) the implementation of optimal regulation through a menu of linear contracts. Our findings are that, for fixed territory, strong economies of scale allow local exchange telecommunications to retain monopoly characteristics even when the (informational) costs of regulation are properly accounted for, the incentive correction term is small in magnitude, and that optimal regulation can be well approximated through relatively simple linear contracts.     

Strategic nonlinear pricing

The objective of this paper is to examine the role of nonlinear strategies in a standard oligopoly framework. We demonstrate that nonlinear pricing may indeed emerge as an equilibrium strategy, but only when firms produce differentiated products, when one firm retains market power due to a cost advantage, or as part of an equilibrium in mixed strategies. In addition, we examine the role of nonlinear pricing in a spatial-competition framework. Our main conclusion is that in highly competitive markets, nonlinear pricing strategies are not likely to emerge as an equilibrium.     

Universal Service: An economic perspective

This paper discusses some important issues that feed the debate on the notion of Universal Service, namely, its definition, justification, cost and financing, within a unified economic framework. In view of the diversity of both the historical and forward looking situations under which the implementation of universal service is envisioned, we provide a systematic analysis of the economic trade-offs associated with various scenarios. We also draw on some actual universal service experiences that have reached some appreciable level of maturity, most notably in telecommunications and postal services, to illustrate and sometimes fine tune some of our arguments.     

The Dynamic Relationship Between Corruption–Inflation: Evidence From Panel Vector Autoregression

This paper aims to explain the mixed causality nexus between corruption and inflation. For that, we apply a panel vector autoregression model on a large sample of 180 countries over the period 1996–2014. Using two corruption indexes and subsample estimations, results provide evidence that the inflation–corruption nexus is bidirectional. The causal effect is more important from corruption to inflation. Interactions remain significant but heterogeneous across subsamples with different income levels. The corruption effect is persistent only in low–middle income economies and its adverse effect on inflation is weaker in high‐income economies. The two‐way relationship between inflation and corruption reflects the inability to control inflation and the situation of the poverty trap in some countries.     

Reliability parameters estimation for parallel systems under imperfect repair

We consider in this paper a parallel system consisting of \(\eta \) identical components. Each component works independently of the others and has a Weibull distributed inter-failure time. When the system fails, we assume that the repair maintenance is imperfect according to the Arithmetic Reduction of Age models (\(ARA_{m}\)) proposed by Doyen and Gaudoin. The purpose of this paper is to generate a simulated failure data of the whole system in order to forecast the behavior of the failure process. Besides, we estimate the maintenance efficiency and the reliability parameters of an imperfect repair following \(ARA_{m}\) models using maximum likelihood estimation method. Our method is tested with several data sets available from related sources. The real data set corresponds to the time between failures of a compressor which is tested by Likelihood Ratio Test (LR). An analysis of the importance and the effect of the memory order of imperfect repair classes (\(ARA_{m}\)) will be discussed using LR test.     

The determinants and impact of telecommunications reforms in developing countries

This paper has two related objectives. First, it seeks to identify the key determinants of some policies that have been at the heart of the reforms of the telecommunications industry in developing countries, namely, liberalization, privatization, and the (re)structuring of regulation. Second, it attempts to estimate the extent to which these policies have translated into actual deployment of telecommunications infrastructure. This simultaneous investigation is conducted by means of an econometric analysis of a 1985-1999 time-series-cross-sectional database on 86 developing countries. Sectoral as well as institutional and financial factors are found to be important determinants of the actual reforms implemented. We uncover a positive relationship between the decision to introduce competition in the digital cellular segment and the growth of the fixed-line segment, suggesting that these two segments have benefited from each other. We also find that countries facing increasing institutional risk and financial constraints are more likely to introduce competition in the digital cellular segment and to privatize the fixed-line incumbent, these policies being economically attractive to both investors and governments. In turn, these policies are those that enhance the deployment of fixed-line infrastructure. In contrast, competition in the analogue cellular segment and the creation of a separate regulator seem to be relatively less attractive policies as they are found to be less likely to be introduced in countries facing increasing institutional risk and budget constraints. Their impact on fixed network deployment is found to be negative or non significant.