Tyler Cowen, Matt Yglesias, and Ryan Avent recently engaged in a fascinating back and forth discussion regarding the role of highways in the development of contemporary American suburbs.
The precise causality—did highway construction cause suburbanization?—is, of course, debatable. But the discussion points to a larger connection between metropolitan development, inequality, and seemingly mundane, unrelated public policy.
Interstate highway construction owes its development to Cold War paranoia and military mobilization. With the Federal-Aid Highway Act of 1956, the federal government devised a transportation plan that would facilitate easy travel for military equipment and soldiers. An extensive highway system, coupled with the affordable production of automobiles and within the context of a consumer-driven economic culture, precipitated suburban housing development.
Of course, that doesn’t exactly explain the racialization of suburban residential patterns. Indeed, it was purposive, intentional, deliberate policies—particularly red-lining and other discriminatory lending policies facilitated by the Federal Housing Authority and officially sanctioned by the federal government—that laid the groundwork for a metropolitan environment initially typified by “chocolate cities, vanilla suburbs.” Within the context of deindustrialization, decentralization, and other impersonal (read: non-deliberately racial) changes in the urban economy, the basis for metropolitan inequality is clear.
That’s not to discount the role of overt racism—you know, like block-busting, racial steering by real estate agents, violent defense of urban and suburban neighborhoods against black “invasion,” and so on—in the creation of racially homogenous suburban neighborhoods. These processes have been well documented by many talented historians. Not to mention racially-charged, failed political struggles over issues like busing and policing that precipitated white flight. And labor market struggles, played out in employment practices and labor union policies. But racism alone can’t explain metropolitan development and residential patterns. No, racism and racial animus shape, and are in turn shaped by, public policy.
Highways made residential development both feasible and desirable in the outer metropolitan fringes, as a suburban populace could easily commute to employment opportunities located within the urban core. It doesn’t exactly explain why individuals and business eventually fled from the inner city (we can thank zoning and tax subsidies for that), but it does illuminate the structure that made such residential patterns possible. It created social and physical distance from which many suburban homeowners could leverage political power, acquire economic resources, and cement inequality.
A policy as simple as highway construction—intended to make military mobility across the nation easier—can nevertheless have dramatic, unintended consequences. Mundane policy may not directly cause, by itself, resulting patterns of disparity; most social phenomena are, after all, multi-causal. Still, it can lay the groundwork—the structure—from which metropolitan inequality materializes.
Direct cause, in this context, matters less than unintentional effect.