Mapping Opportunity

by Alan Leung

New York City is an amalgamation of individual neighborhoods. Although there are shared experiences that unite New Yorkers, the environments that individuals experience day-to-day come in an enormous variety.  This reality is enabled by a transportation system, which for the most part connects us, but can also isolate those neighborhoods that have more limited access to comprehensive public transportation.

The importance of connecting citizens to jobs is frequently discussed as a point of urban policy, but attempts to actually analyze how well connected populations are to job centers is a severely understudied area.  The existence of data on both public transportation service and locations of jobs makes it possible to empirically investigate how many jobs are accessible to a typical citizen via public transit, and how this number varies across the city’s neighborhoods. This article offers a brief introduction to this field of research and identifies how planners might conceptualize the idea of job access in a city such as New York.

The use of public transit routing applications allows researchers to calculate the range an individual could travel within a given time horizon, from a particular starting point.  If we assume a typical commuter is willing to travel no more than 60 minutes each way to reach a job, we can map an individual’s ‘opportunity set’ of neighborhoods in which they could potentially find employment.  In the included maps, zip codes are used as proxies for neighborhoods. By overlaying transit data with economic census information on the jobs found in each neighborhood, it is possible to better understand the actual employment opportunities that are available to a representative individual.  This is a particularly useful exercise in cities like New York where the majority of the work force uses the public transportation system to access a job.

A sample of maps is presented here showing four unique neighborhoods that experience starkly different levels of job access.  It is clear from mapping access that a worker’s spatial opportunity set of employment is not simply a function of linear distance, but is a function of a complex regional transportation network that connects neighborhoods differentially.  The impact of express subway lines, the citing of commuter rail stations and the availability of bus service to fill gaps in the rail system are all evident from these maps, which provide a picture of access that is more consistent with a user’s experience than simple maps of transit routes.

Conceptualizing mobility as a system of overlapping opportunity sets can complement the way policy makers understand so-called place based policies.  Policies that encourage the establishment of work opportunities in high-unemployment or high-poverty neighborhoods often ignore the fact that individuals are highly mobile, and that mobility cannot be well proxied by straight-line geography.  Attempts to subsidize job opportunities in the outer boroughs may ultimately harm the populations they seek to help.  From the maps provided, we can see that all four neighborhoods are able to access Midtown Manhattan within 60 minutes; however, Belmont, Red Hook, and Jamaica all lack access to significant portions of their own borough.  This is an example of how the notion of supporting the ‘local’ job market is a concept more complex than it appears.

Neighborhoods need to be connected to job markets, but more to the point, they need access to jobs that match the human capital of the neighborhood.  This is a nuance to understanding job access that needs to be further developed when modeling opportunity sets.  As this line of research goes forward, planners should be cognizant of the fact that an overarching goal of economic policy must be to connect individuals with jobs.  To this end, we should aim to influence transportation and labor markets so that every individual has an opportunity to share in the economic growth of the region.

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