要旨：Measuring the degree of competition in markets is essential for policy and decision makers. Commonly used structural indices (e.g., HHI) overlook the way in which firms compete, and hence their prices setting in markets. We propose a new measure: the Schedule (Temporal) Differentiation Metric, STDM, which encapsulates firms' market shares as well as the degree of overlap and substitution between their competing services. We demonstrate the STDM using aviation markets and discover a significant improvement in explaining price levels and structure. The information captured by the STDM also explains fares across fare percentiles depending on the competing airlines' business models.

要旨：We develop a two-region model in an overlapping-generations economy with longevity. In our model, we assume household decisions of the number of children and residential location. We examine the relation between life expectancy and spatial agglomeration. Our calibration shows that longer life expectancy promotes agglomeration. Results show that the imbalance of the population distribution between urban and rural area increases as longevity increases. We introduce self-healthcare behavior into the model and show that a higher contribution of self-healthcare intensifies urban agglomeration.

要旨：This study contributes to the literature on the relationship between geographical and relation-based distances of economic agents. We aim to estimate the causal effect of firm’s position in the inter-firm transaction network on its spatial location within a city. Using micro data of inter-firm financial transactions for non-retail firms in Kure, a medium-sized Japanese city, we demonstrate that the more central firms in transaction networks tend to have smaller inter-firm distances and therefore to locate at more accessible places within the city. We estimate that one standard deviation increase in PageRank network centrality implies a decrease of 0.154 standard deviation in the interfirm distance (about 457 meters).