Product Quality Index: A New Way to Classify Intra-industry Trade

The increasing intra-industry trade (IIT) gives an impetus to theoretical foundations of new trade theories. For the empirical assessment, the measurement and segregation of IIT become very essential. On the basis of quality of product, IIT is segregated into two parts. First is based on qualitative differentiation of the products known as vertical IIT (VIIT) and the second is based on the differentiation of the products called as horizontal IIT (HIIT). The work of Greenaway, Hine, and Milner (1994, Weltwirtschaftliches Archiv, 130(1), 77–100), Fontagné and Freudenberg (1997, Intra-industry trade: Methodological issues reconsidered, Paris: Centre d’Études Prospectives et d’Informations Internationales) and Azhar and Elliott (2006, Review of World Economics, 142(3), 476–495) are some of the milestones in the methodological development of IIT. However, these methods are not free from certain shortcomings. Thus, the article attempts to extend the measurement technique with product quality index (PQI) to overcome the existing shortcomings such as arbitrariness of dispersion limit and bias in the classification of IIT into HIIT and VIIT. JEL Code: F140

Generation of dispersive shock waves in nonextensive plasmas

In this research we use a generalized hydrodynamic model to numerically investigate the quasi-neutral expansion and compression of an electron–ion plasma with nonextensive electron velocity distribution into or from vacuum. We study the effects of kinematic viscosity and electron–ion collisions on the expansion profile and compare our results to the numerical solutions of the standard Korteweg – de Vries (KdV) equation. It is found that the quasi-neutrality assumption in the hydrodynamic approach in the absence of viscosity and collisions, which leads to elimination of Poisson’s equation, sets the weak dispersion limit and becomes equivalent to the standard weakly dispersive KdV model. In the weak dispersion limit our model, as well as the KdV with small dispersion effect, predicts that a pulse-like initial profile evolves into solitary wave train. We further show that in a plasma expansion different shock profiles, such as purely dispersive, diffusive–dispersive, and dissipative ones, with significantly different characters may form. Finally, the effect of electron nonextensivity on oscillatory shock waves shows that the expansion profile is affected by changes of q-parameter. Our numerical solution is in qualitative agreement with some distinguished experiments showing the possibility of dispersive shock wave formation in rarefied plasma during an expansion into vacuum.