"Productivity and Metropolitan Density,"  Abstract. This paper evaluates the relationship between urban productivity and density using data on metropolitan areas.  This is an alternative measure of the urban economy to the one employed by Ciccone and Hall (1996).  They used data on output and education by state and employment and education by county, which excludes agricultural and mining sectors.  Instead, our U.S. metropolitan area data are defined contemporaneously for the five available census years from 1950 to 1990.  These data allow us to conduct both cross-sectional and panel analyses.  Furthermore, since we use a model where income is a linear function of density, these data allow us to evaluate the urban system in its own right.  Our results replicate the findings of Ciccone and Hall (1996).  We find that a doubling of population density leads to about a 6% increase in productivity.  Our results establish an important role for Jacobs externalities, measured by metropolitan area population.
 "History versus Expectations: an Empirical Investigation." Abstract.This paper provides the first empirical test of the role of history versus expectations in U.S. urban development.  Starting from Paul Krugman's theoretical work in new economic geography, we test whether or not a modern city develops because of either advantageous initial conditions or by way of a self-fulfilling prophecy based on expectations of development. Using the methodology developed by Granger to establish causality between two variables, but adapted to a cross-section with four time lags, we test whether  asset values, that is, farmland values and housing values, anticipate urban  development or vice versa.  In the case of the former, we would conclude that expectations drive urban development in the U.S., and in the case of the latter we would conclude that history does.  The results indicate very strongly that initial conditions, that is history, dominate the process by which one city becomes a metropolis and another languishes in the periphery.

2001. Stacia A. Neeley, Tufts University, BA, International Relations:
           "Dollarization in Argentina."

2003. Caroline Maes, Tufts University, BA, Quantitative Economics and International Relations:
           "The European Union and the Euro."

2007. Lala Xun Ma, Tufts University, BA,  Quantitative Economics and Mathematics,  and MA in Economics:
          " `I’ll Trust You if I Expect You to Trust Me.' An Analysis of Interpersonal Trust, Friends, and Social Interactions within Social Networks."

The thesis is divided into two parts. The first chapter tests a model of trust by allowing for expectations using the Social Capital Benchmark Survey (2000). We find that trust returns to income and education vary among different groups, and that diversity can increase trust to attain an equilibrium trust level.
In the second chapter, we extend the choice of trust to interactions within social networks and to online social networking. We aim at contributing to the existing literature on social interactions by adding motivation to gain either a weak or strong tie. We find that formal organizations restrict access to those with low-income and low-education, and that online networking can be seen as a weaktie building, informal interaction that becomes a device that bridges social differences between individuals. The policy implications of these results include social diversification in helping organizations attain better economic outcomes, and the importance of access to resources and the Internet in order to decrease socioeconomic differences across communities.

2008. Win (Wirathip) Thanapisitikul, Tufts University,BA Quantitative Economics and Chinese:
           "US House Prices: Dynamics and Spatial Interactions, 1975--2007."

This thesis explains the house price dynamics at the Metropolitan Statistical Area (MSA) level across the continental U.S.
The thesis is broken up into two chapters. In the first chapter, I apply the theoretical and empirical frameworks of
Case and Mayer (1995, 1996) studies of house price variations across cities and towns within the Boston MSA
and extend their theory in order to explain house price variations at the MSA level across the U.S. My results suggest
that the variation in sectoral shift patterns (decline in manufacturing activities) during the late 1990s to early 2000s
throughout the U.S. can help explain the variation in patterns of house price changes. I also find that both
housing affordabilityand the liquidity constraint models fail to fully explain house price variations across MSAs.
In the second chapter, I examine the spatial effects in house price dynamics.Using panel data from 375 MSAs from 1975 to 2007,
I find that, consistent with the positive-feedback hypothesis, there is a spatial diffusion pattern in inter-MSAs house
prices. Specifically, information on lagged price changes in neighboring MSAs (within 200 km) helps explain future
changes in addition to the MSA’s own-lagged price changes. When making home purchasing decisions,
households take into consideration both the lagged prices from the MSA where the house is located and the lagged house
prices in neighboring areas. In fact, they seem to place more weight on the house prices of neighboring areas.
Therefore, this thesis highlights the need to incorporate the spatial dimension into existing house price dynamics models.

Yannis M. Ioannides and Win (Wirathip) Thanapisitikul, Tentative Working Paper

"Spatial Effects and House Price Dynamics in the Continental U.S. " July 8, 2008