Date of Award
Doctor of Philosophy (PhD)
The dissertation is comprised of three essays that analyze the spatial distribution of people and economic activities from three distinct perspectives.
Chapter 1: Explaining the Size Distribution of Cities: X-treme Economies. The empirical regularity known as Zipf's law or the rank-size rule has motivated development of a theoretical literature to explain it. We examine the assumptions on consumer behavior, particularly about their inability to insure against the city-level productivity shocks, implicitly used in this literature. With either self insurance or insurance markets, and either an arbitrarily small cost of moving or the assumption that consumers do not perfectly observe the shocks to firms' technologies, the agents will never move. Even without these frictions, our analysis yields another equilibrium with insurance where consumers never move. Thus, insurance is a substitute for movement. We propose an alternative class of models, involving extreme risk against which consumers will not insure. Instead, they will move, generating a Fréchet distribution of city sizes that is empirically competitive with other models.
(Forthcoming at Quantitative Economics. Based on joint work with Professor Marcus Berliant)
Chapter 2: A Scale-Free Network Structure Explains the City-Size Distribution. Zipf's law is one of the best-known empirical regularities in urban economics. There is extensive research on the subject, where each city is treated symmetrically in terms of the cost of transactions with other cities. Recent developments in network theory facilitate the examination of an asymmetric transport network. In a scale-free network, the chance of observing extremes in network connections becomes higher than the Gaussian distribution predicts and therefore it explains the emergence of large clusters. The city-size distribution shares the same pattern. This paper decodes how accessibility of a city to other cities on the transportation network can boost its local economy and explains the city-size distribution as a result of its underlying transportation network structure.
(Based on joint work with Professor Marcus Berliant)
Chapter 3: A Spatial Production Economy Explains Gross Metropolitan Product. It has long been known that the city-size distribution is fat tailed, drawing the interest of urban economists. In contrast, not much is known about the distribution of GDP at city level (henceforth referred to as gross metropolitan product, GMP). We build a model of the spatial economy that includes production and confirm the following empirical facts about the GMP counterpart of the city-size distribution. First, both Zipf's and Gibrat's law hold for the distribution of GMP as well. In particular the GMP distribution is well-traced by a lognormal distribution. Second, citywide aggregate production exhibits increasing returns to scale with respect to employment. In particular a 1% increase in employment leads to a 1.117% (or 1.180% in theory) increase in GMP. Agglomeration economies are explained as a result of an endogenous trade-off between externalities and land consumption of consumers.
Chair and Committee
John Nachbar, Sukkoo Kim, Alvin Murphy, Bruce Petersen
Watanabe, Hiroki, "Essays on the Size Distribution of Cities" (2015). Arts & Sciences Electronic Theses and Dissertations. 426.