78,496 research outputs found

    Efficiency Analysis of German Electricity Distribution Utilities : Non-Parametric and Parametric Tests

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    This paper applies parametric and non-parametric and parametric tests to assess the efficiency of electricity distribution companies in Germany. We address traditional issues in electricity sector benchmarking, such as the role of scale effects and optimal utility size, as well as new evidence specific to the situation in Germany This paper applies parametric and non-parametric and parametric tests to asses the efficiency of electricity distribution companies in Germany. We use labor, capital, and peak load capacity as inputs, and units sold and the number of customers as output. The data covers 307 (out of 553) German electricity distribution utilities. We apply a data envelopment analysis (DEA) with constant returns to scale (CRS) as the main productivity analysis technique, whereas stochastic frontier analysis (SFA) with distance function is our verification method. The results suggest that returns to scale play a minor role; only very small utilities have a significant cost advantage. Low customer density is found to affect the efficiency score significantly in the lower third of all observations. Surprisingly, East German utilities feature a higher average efficiency than their West German counterparts. The correlation tests imply a high coherence of the results. --Efficiency analysis,econometric methods,electricity distribution,benchmarking,Germany

    Did Global Financial Crisis Impact the Islamic Banking Efficiencies? Evidence From Malaysian Islamic Banks

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    First, this paper investigated the loan and deposit efficiencies of Malaysian Islamic banks during 2008-2013 applying the non-parametric technique, Data Envelopment Analysis (DEA), and found that the average technical efficiency (TE) of loan financing was 83%, 88%, 87%, 95%, 100%, and 94% and the average technical efficiency for deposit mobilizations was 87%, 94%, 94%, 96%, 92%, and 96%. Only four banks in 2008, two bank in 2009, three banks in 2010, two banks in 2011-2013 are both technically and scale efficient in loan production. On the other hand, only four banks in 2008 and 2009, five banks in 2010 and 2011, three banks in 2012, and five banks in 2013 are both technical and scale efficient in deposit mobilizations. Second, the paper compares the efficiencies of Islamic banks between the global financial crisis (GFC) and the post global financial crisis (PGFC) in determining whether the efficiencies of banks between the GFCP and PGFCP are stable. Both parametric and non-parametric tests found no significant difference in the efficiencies between the two periods suggesting that the efficiencies of the Malaysian Islamic banks were stable

    Semi-parametric estimation of joint large movements of risky assets

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    The classical approach to modelling the occurrence of joint large movements of asset returns is to assume multivariate normality for the distribution of asset returns. This implies independence between large returns. However, it is now recognised by both academics and practitioners that large movements of assets returns do not occur independently. This fact encourages the modelling joint large movements of asset returns as non-normal, a non trivial task mainly due to the natural scarcity of such extreme events. This paper shows how to estimate the probability of joint large movements of asset prices using a semi-parametric approach borrowed from extreme value theory (EVT). It helps to understand the contribution of individual assets to large portfolio losses in terms of joint large movements. The advantages of this approach are that it does not require the assumption of a specific parametric form for the dependence structure of the joint large movements, avoiding the model misspecification; it addresses specifically the scarcity of data which is a problem for the reliable fitting of fully parametric models; and it is applicable to portfolios of many assets: there is no dimension explosion. The paper includes an empirical analysis of international equity data showing how to implement semi-parametric EVT modelling and how to exploit its strengths to help understand the probability of joint large movements. We estimate the probability of joint large losses in a portfolio composed of the FTSE 100, Nikkei 250 and S&P 500 indices. Each of the index returns is found to be heavy tailed. The S&P 500 index has a much stronger effect on large portfolio losses than the FTSE 100, although having similar univariate tail heaviness

    Why African stock markets should formally harmonise and integrate their operations

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    Despite experiencing rapid growth in their number and size, existing evidence suggests that African stock markets remain highly fragmented, small, illiquid and technologically weak, severely affecting their informational efficiency. Therefore, this study attempts to empirically ascertain whether African stock markets can improve their informational efficiency by formally harmonising and integrating their operations. Employing parametric and non-parametric variance-ratios tests on 8 African continent-wide and 8 individual national daily share price indices from 1995 to 2011, we find that irrespective of the test employed, the returns of all the 8 African continent-wide indices investigated appear to have better normal distribution properties compared with the 8 individual national share price indices examined. We also report evidence of statistically significant weak form informational efficiency of the African continent-wide share price indices over the individual national share price indices irrespective of the test statistic used. Our results imply that formal harmonisation and integration of African stock markets may improve their informational efficiency

    Robust estimation of intraweek periodicity in volatility and jump detection.

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    Opening, lunch and closing of financial markets induce a periodic component in the volatility of high-frequency returns. We propose a non-parametric weighted standard deviation and parametric truncated maximum likelihood estimation procedure for the periodic component in volatility and show that they are robust to price jumps. We also show that robust periodicity estimates can be used to increase the accuracy of jump detection methods. We compare the classical and robust methods for the 5-minute EUR/USD returns. The robust intraweek periodicity estimates are lower than the classical ones on Tuesday-Friday 8:30-8:35 EST and Monday-Friday 10:00-10:05 EST. The higher values for the non-robust estimates are likely to be due to jumps. Accounting for the periodicity in the volatility of high-frequency returns is especially important to detect the relatively small jumps occurring at times for which volatility is periodically low and to reduce the number of spurious jump detections at times of periodically high volatility.High-frequency data; Jump detection; Periodicity; Robust statistics;

    Why African stock markets should formally harmonise and integrate their operations

    Get PDF
    Despite experiencing rapid growth in their number and size, existing evidence suggests that African stock markets remain highly fragmented, small, illiquid and technologically weak, severely affecting their informational efficiency. Therefore, this study attempts to empirically ascertain whether African stock markets can improve their informational efficiency by formally harmonising and integrating their operations. Employing parametric and non-parametric variance-ratios tests on 8 African continent-wide and 8 individual national daily share price indices from 1995 to 2011, we find that irrespective of the test employed, the returns of all the 8 African continent-wide indices investigated appear to have better normal distribution properties compared with the 8 individual national share price indices examined. We also report evidence of statistically significant weak form informational efficiency of the African continent-wide share price indices over the individual national share price indices irrespective of the test statistic used. Our results imply that formal harmonisation and integration of African stock markets may improve their informational efficiency

    Productivity change using growth accounting and frontier-based approaches – Evidence from a Monte Carlo analysis

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    This study presents some quantitative evidence from a number of simulation experiments on the accuracy of the productivity growth estimates derived from growth accounting (GA) and frontier-based methods (namely Data envelopment Analysis-, Corrected ordinary least squares-, and Stochastic Frontier Analysis-based Malmquist indices) under various conditions. These include the presence of technical inefficiency, measurement error, misspecification of the production function (for the GA and parametric approaches) and increased input and price volatility from one period to the next. The study finds that the frontier-based methods usually outperform GA, but the overall performance varies by experiment. Parametric approaches generally perform best when there is no functional form misspecification, but their accuracy greatly diminishes otherwise. The results also show that the deterministic approaches perform adequately even under conditions of (modest) measurement error and when measurement error becomes larger, the accuracy of all approaches (including stochastic approaches) deteriorates rapidly, to the point that their estimates could be considered unreliable for policy purposes.

    Estimating the Effects of Interest Rates on Share Prices Using Multi-scale Causality Test in Emerging Markets: Evidence from Turkey

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    This paper examines the impacts of changes in interest rates on stock returns by using wavelet analysis with Granger causality test. Financial time series in non-coherent markets should be analyzed by advanced methods capturing complexity of the markets and non-linearities in stock returns. As a semi-parametric method, wavelets analysis might be superior to detect the chaotic patterns in the non-coherent markets. By using daily closing values of the ISE 100 Index and compounded interest rates, it is proven that and starting with 9 days time-scale effect interest rate is granger cause of ISE 100 index and the effects of interest rates on stock return increases with higher time-scales. This evidence shows that bond market has significant long-term effect on stock market for Turkey and traders should consider long-term money markets changes as well as short-term changes.Interest rates; Emerging markets; Wavelets; Stock returns; Multi-scale Granger causality
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