REVISITING THE REAL WAGES–UNEMPLOYMENT RELATIONSHIP. NEW RESULTS FROM NON-LINEAR MODELS

We examine the long-run real wages–unemployment relationship for five OECD countries over the period 1960:1–2001:4. Given the theoretical possibility of non-linear equilibrium due to downward real wage rigidity we employ econometric tests that allow for the presence of non-linearities in the long-run equilibrium. We adopt the notion of 'hidden co-integration' suggested by Granger and Yoon . This methodology has several advantages with respect to other non-linear models. We find statistical evidence that, in general, there is a long-run positive relation between real wages and unemployment only when both are affected by positive shocks. We also find a negative relationship between unemployment and productivity. The empirical analysis is complemented with the estimation of error correction models for all countries.     

Is Moderate Market Performance in the U.S. a Sufficient Condition for Abnormal Returns on CEFs?

In this project, our topic pertains to examination of market efficiency, employing data from closed-end funds (CEFs) trading in the American stock market. Employing both aggregate and individual data, we examine whether or not moderate market performance is a sufficient condition in order to achieve abnormal returns, in the short-run, through exploitation of discount deviations from its mean value. The main hypothesis tested is that market performance affects the mean-reverting properties of CEFs’ discount. Moderate market performance ensures the mean-reversion of CEFs’ discount and points to cointegration between the share prices of CEFs and their net asset value (NAV). Furthermore, when NAV is identified as the common stochastic trend of the system then, market inefficiency is detected.     

Composition versus decomposition in two-stage network DEA: a reverse approach

A two-stage production process assumes that the first stage transforms external inputs to a number of intermediate measures, which then are used as inputs to the second stage that produces the final outputs. The fundamental approaches to two-stage network data envelopment analysis are the multiplicative and the additive efficiency-decomposition approaches. Both they assume a series relationship between the two stages but they differ in the definition of the overall system efficiency as well as in the way they conceptualize the decomposition of the overall efficiency to the efficiencies of the individual stages. In this paper, we first show that the efficiency estimates obtained by the additive decomposition method are biased, by unduly favouring one stage against the other, while those obtained by the multiplicative method are not unique. Then, we present a novel approach to estimate unique and unbiased efficiency scores for the individual stages, which are then composed to obtain the efficiency of the overall system, by selecting the aggregation method a posteriori. Within the particularity of two-stage processes emerging from the conflicting role of the intermediate measures, we develop an envelopment model to locate the efficient frontier whose derivation from our primal multiplier efficiency assessment model is effectively justified. The results derived from our approach are compared with those obtained by the aforementioned basic methods on experimental data as well as on test data drawn from the literature. Similarities and dissimilarities in the results are rigorously justified.     

Productivity, convergence and policy: a study of OECD countries and industries

This paper analyses trends in labour productivity and its underlying determinants in a panel of OECD countries from 1979 to 2002. Data Envelopment Analysis (DEA) is used to estimate a Malmquist measure of multifactor productivity (MFP) change. We decompose the growth in labour productivity into (i) net technological change (ii) input biased technical change (IBTC) (iii) efficiency change and (iv) capital accumulation. We analyse the effect of each of these factors in the transition towards the equilibrium growth paths of both labour productivity and per capita GDP for the OECD countries, controlling for the effects of different policies and institutions. The results indicate that on average gaps in productivity or income levels are narrowing down although there is no evidence to suggest that the entire OECD area comprises a single convergence “club”. Using kernel estimation methods we find that that labour productivity and per capita GDP are settling toward a twin peak (bimodal) distribution. Panel unit root tests over an extended (1960–2001) period provide general support for the convergence hypothesis. Analysis of the contributions of productivity growth within industries and sectoral composition changes show that aggregate productivity change is predominantly driven by ‘net’ within sector effects with very little contribution emerging from sectoral shifts (the ‘in-between’ static or dynamic effects resulting from higher or above average productivity industries gaining employment shares or low productivity industries losing shares).     

The Lead‐Lag Relationship Between Cash and Stock Index Futures in a New Market

This paper investigates the lead‐lag relationship in daily returns and volatilities between price movements of the FTSE/ATHEX‐20 and FTSE/ATHEX Mid‐40 stock index futures and the underlying cash indices in the relatively new futures market of Greece. Empirical results show that there is a bi‐directional relationship between cash and futures prices. However, futures lead the cash index returns, by responding more rapidly to economic events than stock prices. This speed is much higher in the more liquid FTSE/ATHEX‐20 market. Moreover, results indicate that futures volatilities spill information over to the corresponding cash market volatilities in both investigated futures markets, but volatilities in the cash markets have no effect on the volatilities of futures markets. Overall, it seems that new market information is disseminated faster in the futures market compared to the stock market. This implies that the futures markets can be used as price discovery vehicles, providing further evidence that derivatives markets contribute to completing and stabilising capital markets in Greece. A further finding of this study is that futures volume and disequilibrium effects between cash and futures prices are important variables in the explanation of volatilities in cash and futures markets.     

Insider trading and future stock returns in firms with concentrated ownership levels

We investigate the relationship between insider trading and stock returns in firms with concentrated ownership. To this end, we employ data from East Asian countries which span the period January 2003 to May 2012. Consistent with the previous literature, we find a significantly negative relation between the selling activity of insiders and stock returns. However, contrary to studies which focus on highly developed markets, we find that the buying activity of insiders is also inversely related to future stock returns. Our analysis shows that top directors with higher ownership levels drive this result, suggesting that the trading activity of insiders is not always associated with profit-making motives and can be explained by their level of ownership. Furthermore, we demonstrate that a trading strategy which focuses solely on purchases made by top directors with high ownership levels yields negative returns. The paper has important implications for outside investors who mimic the trading activity of insiders with the aim to realise profits.     

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.