要旨：Classical discrete choice models are often used to depict a consumer's micro behavior of which brand to buy; however, they adopt an a priori assumption about a consumer's individual behavior that he or she demands at most unity. This assumption is sometimes unrealistic, especially when the goods analyzed are daily goods, such as food, because a consumer buys multiple units of multiple brands and different consumers demand different amounts. The purpose of this paper is to construct models that allow more flexible individual behaviors that are consistent with the results of discrete choice models. We formulate utility maximization problems that give demand functions equivalent to those from discrete choice models, explicitly taking into account the aggregation structure of consumers, and examine their characteristics from various aspects, such as the form of the utility function, elasticities, and measurement of welfare.

要旨：This note proposes a three-country model of monopolistic competition that captures the role of time zones in the division of labor. The connectivity of business service sectors via communications networks (e.g., the Internet, satellite communications systems) is found to determine the structure of comparative advantage. That is, two countries with connected service sectors have a comparative advantage in the good that requires business services. It is also shown that the third unconnected country inevitably specializes in the good that does not require business services.