Narrow Results

This paper uses two empirical tools to quantify the impact of tariff changes on bilateral trade and welfare. Both tools are rooted in structural gravity literature. The first tool estimates the impact of tariff changes on bilateral trade for 5,020 products in a partial equilibrium framework. The second tool quantifies the impact on bilateral aggregate trade in a general equilibrium setup, allowing estimates of trade diversion and welfare changes. These tools are used to estimate the impact of tariff changes on Armenia with regard to (i) its alignment with the external tariff of the Eurasian Economic Union; (ii) free trade agreements between the Eurasian Economic Union and other economies, including Iran and the People’s Republic of China; and (iii) Armenia’s loss of beneficiary status under the Generalised Scheme of Preferences of the European Union.

Relative permeability (RP) plays a critical role in fluid flow and transport in fracture systems, with considerable advances in theoretical and computational methods over the last few decades. Nevertheless, there is no standard procedure for measuring RP in fractures, and the essential controls on RP in rough fractures are not yet definitive. In this study, we developed a theoretical model to investigate the RP in inclined rough fractures under stress dependence based on fractal theory. The topography of the rough fracture surfaces is well addressed by fractal theory and lubrication theory, and thin bending theory is used to characterize permeability evolution characteristics of fractures under stress conditions. The model accounts for multiple key factors, including the microstructure of the rough fractures (e.g. the fractal dimension, the area ratio, the length ratio, and the maximum and minimum base radii), rock lithology (e.g. elastic modulus and Poisson’s ratio), gravity and effective stress. The predicted results agree well with the available experimental data. It is inferred that the effect of gravity on RP decreases as pressure gradient increases. In general, the theoretical fractal model reveals the coupled flow-deformation mechanisms in fractures, and tends to improve the efficacy of reservoir development strategies. With this new analytical solution, it can help to reduce the uncertainty in flow through fractures and obtain data with high accuracy.

In this paper, we discussed the longitudinal harmonic waves reflection from a solid elastic half-space with electromagnetic and gravity fields influence, considering a fractional order via fractional exponential function method. The clarifications are required for the reflection amplitudes ratios (i.e. the ratios between the reflected waves amplitude and the incident waves amplitude). The results obtained were calculated analytically and displayed by graphs to show the physical meaning of the phenomenon. A comparison has been made between the fractional and integer derivatives. The results of this paper demonstrate the rigor and effectiveness of the considered fractional technique.

This paper examines the extent to which cultural proximity influences, and is influenced by, bilateral trade flows. Variables measuring common language or religion, commonly considered to be measures of cultural proximity, have been found to be highly significant in explaining the volume of trade between countries, but these measures have the distinct disadvantage of being static; they do not change over time. In fact, however, culture does change, possibly in response to exposure to the foreign goods, methods, and ideas brought across borders by trade; the cultural "distance" between two countries can therefore be seen to fall or rise over time. In this paper, responses to World Values Survey questions regarding trust, respect, control, and obedience are used to create a measure of cultural distance. I use this cultural distance variable in gravity regressions and show that more culturally-distant countries trade less, but that more traditional measures of culture are more significant in explaining trade. I then explore the determinants of cultural distance, finding that exports reduce cultural distance.

We argue that using the aggregate of the Euclidian distance of different dimensions of culture to measure the impact of culture on bilateral trade patterns as is conventional in the literature is flawed. Using recent innovations in gravity model estimations and adopting the GLOBE team dimensions of culture, we confirm that the aggregate measure of culture imposes arbitrary functional forms, wrongly assumes symmetry in the effect of culture on bilateral trade, generalizes the effect of culture on trade and lacks policy relevancy. Our novel approach also allows us to determine which aspects of culture promote trade and which aspects do not.

Many improvements have been proposed for the basic gravity model specification, most of which are confirmed by standard statistical tests due to the large number of observations often used to estimate such models. We use Monte Carlo experiments to examine situations in which features of models may be found statistically significant (or insignificant) when it is known ex ante that they are absent (or present) in the underlying data process. Erroneous assumptions about the presence or absence of lagged dependent variables, fixed effects, free-trade associations and custom unions are shown to introduce an economically important bias in estimates of the coefficients of interest, and in some cases to be confirmed spuriously. Policy effects for such initiatives as free trade associations and currency unions can also be confirmed spuriously when they do not exist in the data-generating process.

Maximum residue limits (MRLs) on pesticides and veterinary drugs in plant and animal products are established to promote food safety and animal and plant health. In practice, however, they are often accused of creating unnecessary trade barriers. The controversy is more prominent when a given MRL is stricter than the corresponding international standard developed by Codex. Using the score indices constructed by Li and Beghin (2012), we empirically assess the implications of stringency in MRLs in plant and animal products, relative to Codex levels, for Canadian and US trade performance. We find little evidence that US imports are influenced by domestic stringency or those imposed by its trading partners. However, US exports are negatively affected by stringency in destination markets. Canada’s stringent MRLs facilitate its exports of plant and animal products and these exports do not seem to be impeded by MRL stringency in destination markets. Canada’s imports do not appear to be systematically influenced by either its own or its trading partners’ MRL stringency. We draw implications for the potential harmonization of MRLs between the two countries.