From the beginning of the 1980s, the first theoretical analysis of
intra-industry trade showed that the determinants and consequences of this type
of trade are different, depending on whether the traded products differ in
quality. When the products are subject to intra-industry trade between two
countries with distinct qualities, this trade is vertically differentiated.
Otherwise, it is called horizontal differentiation. There is a method for
distinguishing intra-industry trade between two countries in vertical
differentiation from those in horizontal differentiation. This method compares
exports' unit value to imports for each industry's intra-industry trade. It
considers the intra-industry trading carried out in this industry as vertical
differentiation when the unit value of exports differs significantly from that
of imports. This approach has limitations. The discussion below will lead us to
think about an alternative method for separating and measuring intra-industry
trade into horizontal and vertical differentiation.Comment: 12 page