Network modeling approaches for calculating wholesale NGA prices: A full comparison based on the Greek fixed broadband market

According to the European Commission Recommendation for setting copper and fiber wholesale prices where cost orientation is imposed as a remedy, National Regulatory Authorities (NRAs) should adopt a Bottom-UP Long-Run Incremental Cost Plus (BU LRIC+) costing methodology that estimates the current cost that a hypothetical efficient operator would incur to build a modern efficient Next Generation Access (NGA) network. The starting point of modeling an efficient operator investing in NGA networks is the network modeling approach. In this paper, we compare the most widely adopted network modeling approaches in terms of wholesale fiber-to-the-home (FTTH) prices. In particular, the modified scorched node approach is compared to the extreme cases of the scorched node and the scorched earth approaches. The comparison between the aforementioned scenarios sheds light on the impact of each approach on the wholesale FTTH prices. The main finding of this paper is that the scorched earth approach leads to a maximum of 10% reduction in the short-term access prices compared to the most inefficient scorched node approach, whereas further extending its optimizations by optimizing the number of central offices, both the short-term and long-term wholesale price reductions are quite significant (more than 20%) regardless of service speeds. Consequently, NRAs should consider a geographically differentiated modeling approach when regulating the wholesale market by adjusting the level of scorching in each area and network segment according to the investment plans of telecom operators. An appropriate variation of the modeled network operator's efficiency is expected to more accurately represent the costs of a reasonably efficient operator based on the real market conditions and a forward-looking perspective. These findings provide valuable information to both network operators and telecom regulators.     

Interrogating Sickonomics,from Diagnosis to Cure: A Response to Hodgson

Hodgson's review of our books argues against us that marginalism neither adopted methodological individualism nor excluded the social from economics. Thus, he finds a partial solution to sickonomics in abandoning the term methodological individualism and using both structures and individuals as analytical starting point(s), revisiting Marshallian marginalism dressed up in socio-institutional clothing. He also denies any relationship between the current malaise in economics and the marginal revolution, as we claim, focusing exclusively on institutional developments since the Second World War. We show Hodgson is either partial or wrong on all of these counts. Firstly, his alternative to methodological individualism is untenable. Secondly, institutions, although implicitly present in Marshallian and Walrasian economics, play no substantive analytical role and as such are superfluous. Finally, although institutional factors help explain the sickness of modern economics (in addition to socioeconomic, ideological, political, and intellectual factors), the intellectual roots of this decay lie in the conceptual framework established around the marginal revolution.     

Cointegration Tests Of The Monetary Exchange Rate Model: The Canadian—U.S. Dollar, 1970 – 1994

Using data on the Canadian-U.S. dollar rate, we reexamine the monetary model of exchange-rate determination for the recent float in three ways. First, we test its long-run validity, using Johansen's multivariate cointegration techniques. Second, we examine and test the model for the presence of speculative bubble, and finally we test for parameter stability of Johansen's results using the Hanse-Johansen recursive tests. [F31]     

Productive efficiency and firm exit in the food sector

This work examines the effects of productive efficiency on the survival of firms in the Greek food sector. Technical and scale efficiency scores are computed within a data envelopment analysis (DEA) framework and are used as explanatory variables in a parametric (Weibull) survival model. High technical efficiency increases the median survival time and lowers the hazard rate of exit. As the scale efficiency of a firm operating either at increasing or decreasing returns to scale approaches one (1), its theoretically maximum value, the expected median survival time, is maximized for all types of exits. Developments in biotechnology, the evolution of alternative food supply networks, innovations in the food sector and competition policy are likely to affect technical and scale efficiency of food manufacturing firms. Results unraveling the effects of technical and scale efficiency on the survival of firms in the food sector are of particular relevance to food policy makers.     

Innovation diffusion with generation substitution effects

Markets of high technology products and services, such as telecommunications, are described by fast technological changes and rapid generational substitutions. Since the conventional modeling approaches that are based on diffusion models do not usually incorporate this important aspect into their formulations, the accuracy of the provided forecasts is consequently affected. The work presented in this paper is concerned with the development of a methodology for describing innovation diffusion, in the context of generation substitution. For this purpose, a dynamic diffusion model is developed and evaluated, based on the assumption that the saturation level of the market does not remain constant throughout the diffusion process but is affected by the diffusion of its descendant generation, as soon as the latter is introduced into the market. In contradiction to the conventional diffusion models, which assume static saturation levels, the proposed approach incorporates the effects of generation substitution and develops a diffusion model with a dynamic ceiling. The importance of such an approach is especially significant for markets characterized by rapid technological and generational changes. Evaluation of the proposed methodology was performed over 2G and 3G historical data and for a number of European countries, providing quite accurate estimation and forecasting results, along with important information regarding the rate of generation substitution.     

The short-term impact of director trading in UK closed-end funds

Most closed-end funds are transparent entities that hold securities that are actively traded in liquid markets. In such a setting, the argument that director transactions mitigate information asymmetry has very limited applicability. Our results provide support for the theory of Barber and Odean [2008. “All that Glitters: The Effect of Attention and News on the Buying Behavior of Individual and Institutional Investors.” Review of Financial Studies 21: 785–818]: retail investor decision-making is influenced by attention-grabbing events. Director purchases are one such attention-grabbing event and are associated with significant positive price returns – the magnitudes of which are linked to the size of the purchase, the size of the fund, and the investment mandate. Trading volumes increase at the time of the purchase but most of the initial price responses and trading volumes dissipate over the following 15 days.     

Economic efficiency of Greek retail SMEs in a period of high fluctuations in economic activity: a DEA approach

This study aims to analyse the economic efficiency of Greek small and medium retail enterprises before and after the crisis that started in 2008. Based on the Accounting Equation, we use Data Envelopment Analysis (DEA) to estimate variable returns of scale efficiency scores and to conclude on specific characteristics that efficient companies have, for example, on capital structure. Our results from the DEA application show a high degree of inefficiency. We found that SMEs on the islands are more efficient than those on the mainland and that SMEs in the cities are the least efficient. Size seems to be important, more so on the islands and on the mainland than in the cities. We conclude that companies should act more conservatively in terms of operating cost when the first signs of a recession appear. In addition, during a recession period, companies that have evidences that their operations will continue positively should strengthen their operations by raising more own capital. Finally, our study clarifies four issues: the efficiency of retail companies in a period of growth and a period of recession, focusing on SMEs that operate in different regions, connecting Accounting Equation and DEA and adding acid ratio as an output in our model.     

Investments in next generation access infrastructures under regulatory uncertainty

This article studies the impact of regulatory uncertainty on an incumbent’s incentives to undertake the socially optimal investments in NGA networks. Thus, a regulatory non-commitment setting in which the regulator sets the access price after the deployment of the NGA network is used. In particular, it is assumed that the regulator sets the access price at the marginal cost of providing the access with some probability and gives an access markup, which equals the average cost of the investments, with the complementary probability. It is found that when the slope of the marginal investment cost function is not particularly steep in relation to the impact of investments on demand, the incumbent underinvests compared to the socially optimal investment level. On the contrary, in a more realistic case when the impact of investments on demand is low in relation to the slope of the marginal investment cost function, the incumbent may overinvest or underinvest depending on the probability of incorporating an access markup into the access price.     

Firm efficiency and stock returns

In this paper, we investigate the role of firm efficiency in asset pricing using a sample of US publicly listed companies for the period 1988–2007. We employ non-parametric data envelopment analysis (DEA) on various input/output combinations, focusing on sales and market value as output measures in the construction of the frontier technologies. Using these performance measures, we examine whether efficient firms perform differently from inefficient firms following standard financial analysis procedures. First, we employ performance attribution regressions, by forming portfolios based on efficiency scores and tracking the performance of the various portfolios over time. Second, we perform cross-sectional/panel regressions to determine whether firm efficiency indeed has explanatory power for the cross-section of stock returns. Our results suggest that firm efficiency plays an important role in asset pricing and that efficient firms significantly outperform inefficient firms even after controlling for known risk factors.     

Empirical size and power of some diagnostic tests applied to a distributed lag model

We produce Monte Carlo evidence on the size and power of the RESET, a heteroscedasticity test, and a test for autocorrelation applied to realistic distributed-lag models. We find that the autocorrelation test has the correct size and high power to detect not only autocorrelation (given a correct model), but also the erroneous omission of several lags of an explanatory variable, whereas the RESET and heteroscedasticity tests are oversized in the presence of positive disturbance autocorrelation, especially when the regressors are also positively autocorrelated, and have no power to detect such misspecification errors. In large samples, size distortion may be avoided by using autocorrelation-robust methods.