The Z-axis: Elevation gradient effects in Urban America

This paper presents an in-depth analysis of hilliness effects in American urban communities. Using data from seventeen cities, we establish robust relationships between topography and density, income and housing value gradients. We find that high-income households display strong preference not only for higher altitude but also for unevenness, leading to spatial income stratification at both the city and tract-level. We analyze potential causes of this propensity: micro-climate, crime, congestion, view effects, and use of public transit. We conclude that multi-dimensional spatial methods are crucial to investigations of cities with substantial unevenness. Moreover, redistributive social and economic policies must struggle with a fundamental, topographical dimension to inequality.