Dick Spotswood: Statistics clash over number of commuters working in Marin

Dick Spotswood: Statistics clash over number of commuters working in Marin  see it in the Marin IJ. Great comments too.

By Dick Spotswood
spotswood@comcast.net

Posted:   06/28/2014 08:02:13 PM PDT29 Comments


Statistics are powerful. One number that has driven the debate over so-called transit-centered housing is a figure published by Marin's League of Women Voters. In its white paper, "Dispelling the Myths Surrounding Affordable Housing," the league states, "59.5 percent of Marin workers commute from outside the county."

Its idea is that if Marin builds more housing, this environmental and social negative will dissipate.

The number may be a "myth." At the very least, it's seriously in dispute.
From my review, the most reliable and detailed information comes from the U.S. Census Bureau's report, "Residence county to work place county, 2006-2010." That exhaustive review indicated the actual percentage of workers who in-commute to Marin is 35.7 percent.

That's quite a difference from the league's claim.

According to census data, 120,586 Marinites travel to a job. Of those, 78,950 both live and work in Marin. The in-commute consists of 42,657 travelers who live in another county but work in Marin. It's no surprise that the largest influx is the 17,457 Sonoma residents traveling each day to work in Marin.

This makes sense. It's actually a big part of the justification for the Sonoma-Marin Area Rail Transit train. The commuter train is essentially designed to move Sonoma residents to Marin jobs, a worthy goal.

About 41,600 Marinites, 34 percent of our workers, are outbound commuters with most headed to San Francisco and Contra Costa County.

The second-largest source of Marin's workers are San Franciscans. While San Francisco's housing prices are even greater than Marin's, some younger workers preferring the city's urban experience have landed well-paying Marin jobs. Contra Costa, Solano and Alameda counties, in declining order, are the other prime sources of Marin's in-commuting.
The league's numbers are based on a second database. That's the Census Bureau's "Longitudinal Employment and Household Dynamics" program.

The conflicting numbers are due to different sources of data.

"Residence-to-work place" statistics are based on surveys, which admittedly could have sampling errors.

The "longitudinal dynamics" figures are based on unemployment data that doesn't include the self-employed, informally employed and selected federal employment categories. Disregarding the substantial number of self-employed Marinites makes those numbers dubious.
The Census Bureau acknowledges the discrepancy. They're working on reconciliations, but since it's a national phenomena, don't expect a resolution anytime soon.

It's the nature of the polarized housing debate that Marin and similarly situated suburban counties face, that when conflicting statistics arise, proponents of various views adopt as gospel numbers that justify their preconceived position.

Marin's League of Women Voters in a laudable organization, but don't forget they play two roles.
The more obvious is as nonpartisan guardian of fair elections. Its second role is advocacy. Here, its members are not neutral arbiters but proponents, in this case, for affordable and high-density housing.

As such the origin and destination statistics touted in their "Myths" report must be judged accordingly.

The league frankly acknowledges both databases, but prefers to publish the numbers that support their position as housing advocates.

Use the league's numbers and Marin has the worst share of in-commuters of any Bay Area county. Follow the Census Bureau's Residence-to-Work Place data and Marin's in-commute is average with both San Francisco and San Mateo having more in-commuters than Marin.
Given the dynamics of America's free enterprise society with folks holding multiple jobs during their careers, decisions on job locations and residence are based on many factors.
A good job isn't often passed up simply because it involves a commute, and building more dense housing isn't inherently going to change that necessity.

None of this takes away the need for more affordable housing. The problem is that rational decision-making is derailed when important statistics are used selectively.


Dick Spotswood of Mill Valley writes a twice-weekly column on local politics for the Marin Independent Journal.