An investigation of cointegration and casualty relationships between the PIIGS’ stock markets

The aim of this paper is to investigate the relationship of price changes in the southern European E.U. member states through their stock markets and especially among the exchange markets of Portugal, Italy, Ireland, Greece and Spain, known also as the PIIGS countries. More specifically, it is examined whether cointegration and causality relationships exists among the PIIGS’ Stock Markets while by testing these relationships the existence of the Efficient Market Hypothesis (EMH) among these stock markets is also tested. In case of cointegration relationships between these markets it is proved that possible advantages by internationalizing portfolio diversification are limited and further attention must be given for the selection of an internationalized optimal portfolio. It is also wealth mentioning that since 2012 Europe faces a serious economic crisis which is deeper in the member states of the South, so even further attention must be given to the construction of optimal portfolios.peer-reviewe

Business cycles in Greek maritime transport: an econometric exploration (1998–2015)

Maritime transport has been a crucial input for the growth of the Greek economy given that the Greek fleet is one of largest merchant fleets in the world. However, the impact of the local and international business cycle on Greek maritime transport is inadequately researched, so far, in the literature. In this context, the present paper investigates the key determinants of maritime transport fluctuations in the three major ports of the Greek hinterland, taking into account a number of variables for the 1998–2015 time-span, capturing, at least partly, the global financial crisis and the local crisis, as well. To this end, various relevant quantitative techniques have been used, such as Granger causality, Dufour and Renault multistep causality and SURE system estimation. Our main finding is that Greek maritime transport traffic, as expressed through the cargo volumes of the three major ports of Piraeus, Volos and Thessaloniki, has not been influenced by the Greek business cycle, implying that the country’s maritime sector is practically independent of the macroeconomic conditions of the total economy. Clearly, future and more extended research would be relevant in the direction of applying the aforementioned approach to other EU countries of the Mediterranean

A New Invasion of the Common Slider on a Mediterranean Island (Lesvos, Greece): A Potential Threat to Native Terrapin Populations?

Island wetlands are considered crucial to biodiversity due to their unique ecological, biogeographical, and socioeconomic dynamics. However, these habitat types are particularly vulnerable to invasion; invasive species can cause severe ecological, evolutionary, and epidemiological impacts on native species. One of the most important invasive species, the common slider Trachemys scripta, an opportunistic inhabitant of freshwater habitats, has been released in multiple localities across Greece in recent years, and has expanded its range through random and unintentional releases in the Aegean islands. Since its first documented record on the island of Crete in 1998, the species has been observed on six more islands. Here, we report, for the first time, two subspecies of the common slider (T. scripta scripta and T. scripta elegans) on the wetlands of the island of Lesvos. We discuss the potential threats to native terrapins and we examine whether the introduction of this invasive species has affected native terrapins by monitoring their populations for 12 consecutive years (2010–2022). We found the common slider in 3 out of 110 wetlands surveyed. At one site, we document the presence of invasive terrapins belonging to two different subspecies. In all surveyed wetlands, we found stable populations of the two native freshwater terrapins, Mauremys rivulata and Emys orbicularis, with the first species found in much larger populations than the second. Despite these reassuring findings, the presence of this introduced species on the island of Lesvos raises serious concerns regarding its negative effects on the local terrapin populations. We propose that systematic and thorough monitoring of insular wetlands, as in the case of Lesvos, should be adopted on other islands as well, with priority on those where the common slider has been recorded

Spatiotemporal Patterns and Road Mortality Hotspots of Herpetofauna on a Mediterranean Island

Traffic intensification, often in conjunction with habitat fragmentation, has caused frequent roadkill incidents, particularly among reptiles, amphibians, and other taxa. Herpetofauna species, which are slow moving and habitat dependent, are particularly susceptible to these incidents because they often use roads during thermoregulation. Lesvos, the eighth-largest Mediterranean island, boasts a biodiversity that surpasses most other Mediterranean islands of similar or larger size, with a plethora of herpetofauna species inhabiting its terrain. In recent years, new roads were constructed on Lesvos, which are considered to be one of the most important factors that negatively affect the island’s wildlife as they increase the non-natural mortality of animals, are obstacles to their mobility, and reduce the connectivity of populations by limiting their dynamics. In the present study, we examined the road mortality of amphibians and reptiles by analyzing (a) the temporal and seasonal patterns of such incidents, (b) the relationship between roadside habitats and road network characteristics with the roadkilled herpetofauna species, and (c) their spatial distribution on Lesvos during the years 2009–2012 and 2016–2019. To identify significant clusters of reptile and amphibian roadkills, we performed hotspot analysis by utilizing kernel density estimation and Getis Ord Gi* statistics. We recorded a total of 330 roadkills among 20 species, with the highest rates emerging among the European green toad (Bufotes viridis), the European glass lizard (Pseudopus apodus), the Rhodos green lizard (Lacerta diplochondrodes), and the snake-eyed lizard (Ophisops elegans). Spatial statistical analysis revealed that roads close to herpetofauna habitats exhibit statistically significant clusters of roadkills that intensify during the spring season. Regular monitoring and mapping of herpetofauna road mortality will enable the implementation of management strategies to mitigate the negative impact of this phenomenon

Estimating the demand for ADSL and ISDN services in Greece

The aim of this paper is to investigate the demand for broadband services in Greece and to estimate the price elasticity of the demand for ADSL and ISDN services as well as the cross-price elasticity between the two services. The empirical analysis uses the 384 kbps connections since for the period examined, over 85% of the total ADSL customers in Greece are connected at this bandwidth. The empirical analysis is based on an ad-hoc specification of the demand equation, with no reference to the utility maximization problem of the representative consumer. The results of the analysis show that both demands are inelastic. In addition, cross-price elasticity for ADSL is negative, indicating that ISDN is a complement to ADSL, whereas the demand for ISDN is almost neutral to ADSL.Broadband ADSL ISDN Own-price elasticity Cross-price elasticity

COVID-19 and the Energy Price Volatility

The challenges of the world economy and their societies, after the outbreak of the COVID-19 pandemic have led policy-makers to seek for effective solutions. This paper examines the oil price volatility response to the COVID-19 pandemic and stock market volatility using daily data. A general econometric panel model is applied to investigate the relationship between COVID-19 infection and death announcements with oil price volatility. The paper uses data from six geographical zones, Europe, Africa, Asia, North America, South America, and Oceania for the period 21 January 2020 until 13 May 2021 and the empirical findings show that COVID-19 deaths affected oil volatility significantly. This conclusion is confirmed by a second stage analysis applied separately for each geographical area. The only geographical area where the existence of correlation is not confirmed between the rate of increase in deaths and the volatility of the price of crude oil is Asia. The conclusions of this study clearly suggest that COVID-19 is a new risk component on top of economic and market uncertainty that affects oil prices and volatility. Overall, our results are useful for policy-makers, especially in the case of a new wave of infection and deaths in the future