in a few countries (or maybe just one). This logic explains how each country may specialize in producing a few brands of any given type of product, instead of specializing in different types of products. Krugman modeled a 'preference for diversity' by assuming a CES utility function like that in a 1977 paper by Avinash Dixit and Joseph Stiglitz. Many models of international trade now follow Krugman's lead, incorporating economies of scale in production and a preference for diversity in consumption. This way of modeling trade has come to be called New Trade Theory. Krugman's theory also took into account transportation costs, a key feature in producing the "home market effect", which would later feature in his work on the new economic geography. The home market effect "states that, ceteris paribus, the country with the larger demand for a good shall, at equilibrium, produce a more than proportionate share of that good and be a net exporter of it". The home market effect was an unexpected result, and Krugman initially questioned it, but ultimately concluded that the mathematics of the model were correct. When there are economies of scale in production, it is possible that countries may become 'locked into' disadvantageous patterns of trade. Krugman points out that although globalization has been positive on a whole, since the 1980s the process known as hyper-globalization has at least played a part in rising inequality. Nonetheless, trade remains beneficial in general, even between similar countries, because it permits firms to save on costs by producing at a larger, more efficient scale, and because it increases the range of brands available and sharpens the competition between firms. Krugman has usually been supportive of free trade and globalization. He has also been critical of industrial policy, which New Trade Theory suggests might offer nations rent-seeking advantages if "strategic industries" can be identified, saying it's not clear that such identification can be done accurately enough to matter. New economic geography It took an interval of eleven years, but ultimately Krugman's work on New Trade Theory (NTT) converged to what is usually called the "new economic geography" (NEG), which Krugman began to develop in a seminal 1991 paper, "Increasing Returns and Economic Geography", published in the Journal of Political Economy. In Krugman's own words, the passage from NTT to NEG was "obvious in retrospect; but it certainly took me a while to see it. ... The