A phenomenographic study of Greek primary school students’ representations concerning technology in daily life

The present research investigated and studied students’ representations about daily life technologies, in a prospect of studying technology in Greek primary education. In the research participated 60 Greek primary school students aged 9 to 12 years old. Research data were collected through semi-structured, personal, clinical-type interviews. Each interview investigated student’s conceptions and views about the following thematic areas: the concept of technology, daily life technologies, technological change, and the impact of technology use in everyday life. Data analysis revealed that the majority of students equated technology with modern tools and appliances, especially with computers, TV, mobile phones, satellites and other micro- and macro-technologies, whereas experience based technologies (de Vries, Technology education: Beyond the “technology is applied science” paradigm. J. Technol. Edu. 8 (1996), 7) have been hardly recognized by them as technology. Also students’ representations can be categorized either as technology-oriented representations, which focus on a collection of technical means without reference to humans, or as human-oriented representations, focused on technical means with substantial reference to human needs and activities. Depending on these types of representations, students seem to conceive differently the nature of the problems, which they recognize that the wide use of technology causes mainly to the environment and the responsibility of the user for these problems. Moreover, it seems that the concept of technological change is a quite difficult one for the students. In order to help students form adequate representations about daily life technology and technological change an appropriate teaching approach was designed on the basis of these students’ representations.     

Sample size determination of binomial data with the presence of misclassification

We propose a double sampling scheme with two classifiers to address the problem of optimal sample size when misclassification among binomial observations is observed. The classifiers vary with respect to the classifying cost and precision. Furthermore, since the data are unknown, an additional constraint is set on the probability of observing ``undesirable' data. The method is developed following the Bayesian point of view.     

The hard shadow of the Greek economy: new estimates of the size of the underground economy and its fiscal impact

This article presents new estimates of the Greek underground economy and explores the link between the underground economy and aggregate debt. We show that the Greek underground economy has been underestimated heavily and has been on a rising trend again since Greece adopted the Euro. We also present evidence that the size of the underground economy is positively related to the debt-to-GDP ratio, implying that fighting the underground economy is also conducive to financial and macroeconomic stability. Our results suggest that for our sample of 11 EMU member countries, the loss of the inflation tax as an economic policy instrument had drastic consequences. While the underground economy did not have a statistically significant impact on aggregate debt before the introduction of the Euro, it has pushed up the debt-to-GDP ratio in our sample since.     

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.

Land and Its Taxation as Issues in Economic Theory: What Is the Reason for Their Eclipse?

A bstract . Despite the continuing practical importance of the subject, land and its taxation have lost their prominence in modern economic theory. This evolution in economic thought is traced briefly. An explanatory hypothesis is offered based on the theoretical bias of the two major traditions in neo-classical theory : the Marshailian tradition does not distinguish land from capital (treating land as only one among many forms of capital) while the Walrasian tradition cannot distinguish capital from land (treating capital as an "original" factor similar to land). Though both Alfred Marshall and Léon Walras had a considerable interest in questions of land taxation, their followers, on the whole, have been neither able to overcome nor have they even been aware of the confinement of their respective theoretical perspectives.     

A Stochastic Production Frontier Estimator of the Degree of Oligopsony Power in the U.S. Cattle Industry

The objective of this study is to estimate the degree of oligopsony power in the U.S. cattle industry with the use of the recently developed stochastic frontier estimator of market power. Unlike the seminal paper where estimation of the mark-up in an output market at firm level was the main objective, this work proposes a stochastic production frontier estimator in order to estimate the mark-down in an input market at aggregate level. Furthermore, with the help of the new estimator we derive and estimate the Lerner index of oligospony power for the U.S. cattle market. For the empirical part of the study we employed annual time series data from the U.S. cattle/beef industry for the time period 1970-2009. Our results suggest that beef packers exert market power when purchasing live cattle for slaughter.