1,720,958 research outputs found
Spatial Integration and Asymmetric Price Transmission in Selected Iranian Chicken Markets
Get PDFThis study evaluates pattern of price adjustments in selected spatially separated chicken markets in Iran using weekly price data from 1998:17 to 2006:41 including 441 observations in total. The results of Tsay’s test suggest that threshold behavior characterize spatial price linkages among the selected markets that imply on using the threshold models. We use the multi-dimensional (two and three regime) threshold cointegration of TAR and M-TAR models. Our results confirm the different speed of adjustment in response to positive and negative shocks in every case. We also utilize impulse response function to investigate dynamic patterns of adjustments in response to shocks.Spatial Integration, Price Transmission, Threshold Autoregression, Chicken, International Relations/Trade, Marketing,
Spatial Integration and Asymmetric Price Transmission in Selected Iranian Chicken Markets
Get PDFThis study evaluates pattern of price adjustments in
selected spatially separated chicken markets in Iran using
weekly price data from 1998:17 to 2006:41 including 441
observations in total. The results of Tsay’s test suggest that
threshold behavior characterize spatial price linkages among
the selected markets that imply on using the threshold models.
We use the multi-dimensional (two and three regime)
threshold cointegration of TAR and M-TAR models. Our
results confirm the different speed of adjustment in response
to positive and negative shocks in every case. We also utilize
impulse response function to investigate dynamic patterns of
adjustments in response to shocks
Seasonality and Forecasting of Monthly Broiler Price in Iran
Get PDFThe objective of this study was to model seasonal behavior
of broiler price in Iran that can be used to forecast the
monthly broiler prices. In this context, the periodic autoregressive
(PAR), the seasonal integrated models, and the Box-Jenkins
(SARIMA) models were used as the primary nominates for the
forecasting model. It was shown that the PAR (q) model could
not be considered as an appropriate method for modeling
seasonal behavior of the broiler price. Results of seasonal unit
root test indicated that the monthly prices of broiler follow a
non-stationary stochastic seasonal process. Accordingly, the regression-based
model is an appropriate modeling framework.
While SARIMAis an alternative modeling approach, the RMSE
of forecasting error suggested the superiority of the regressionbased
model over the SARIMAmodel. Therefore, the estimated
parameters of the regression-based model can be used to predict
the monthly prices of broiler in Iran
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Modeling Asymmetric Effects of Exchange Rate Fluctuations on Agricultural Trade Balance: Evidence from Iran and Iraq
Get PDFThe exchange rate plays a crucial role in foreign trade and has asymmetric effects. This study examines the asymmetric effects of exchange rate volatility on the trade balance in the agricultural sector between Iran and Iraq, using the non-linear ARDL model from 1998 to 2020. The results show that Iraq's GDP and oil price fluctuations positively affect the trade balance. In contrast, Iran's GDP and the U.S. economic sanctions against Iran have negative and significant effects on the trade balance of Iran with Iraq in the agriculture sector. The results do not confirm the existence of the J-curve effect in the trade relations between Iran and Iraq, because an increase in the bilateral exchange rate, in both the long-run and short-run, improves the trade balance of Iran with Iraq in the agriculture sector. Furthermore, the positive and negative fluctuations of the bilateral exchange rate have different effects on the trade balance. While the devaluation of the national currency does not cause a downward trend in the short run, the exchange rate policy can improve the trade balance from the beginning
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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