Thursday, October 27, 2005

New Census numbers on daytime population

Last week the Census Bureau released new numbers estimating the daytime population of various cities and counties - meaning the resident population plus incoming commuters for the day. The goal is to have better data for transportation and disaster planning. If an evacuation situation occurs in a city, you have to evacuate all those daytime commuters in addition to the resident population. Just looking at the normal residential population would be misleading.

Various data tables are also available. Table 1 is particularly interesting, with a comparison of the top 10 cities. Houston has the third-largest numerical daytime population increase in the nation, with 403,313 new people coming in each day (a 20% increase), not far behind #2 DC at 410,794 and #1 NY at 563,060. Those three cities are significantly ahead of all the other large cities, which range from around a 100 to 260 thousand. Even cities with substantial heavy rail transit systems like Boston, SF, Philly, and Chicago don't bring in nearly as many commuters as we do.

Houston also has the highest employment to resident ratio of the ten largest cities at 1.48. Dallas is a close #2 at 1.42, but everybody else is way down between 1.09 and 1.24. What does this mean? It means we've been able to hold on to the lion's share of the metro job base (and the resulting commercial tax base), rather than it leaking out to the suburbs. We've been able to do this with a combination of annexation and massive freeway and HOV transportation investments into the core. Los Angeles has the worst traffic congestion of the top ten cities, and also has the lowest ratio at 1.09 - their jobs and employers have dispersed out to the suburbs.


At 1:12 PM, October 29, 2005, Anonymous Anonymous said...

Tory I am not satisfied with your explaination for why Houston has been able to keep so many jobs in the cores. It seems that while we do have an excellent transportation system that primarily serves downtown and the Galleria, most other cities also do, and even more so with them often being the hubs for multiple forms of transit. I am not sure what it is, but It seems like it has to be something else also.

At 1:40 PM, October 29, 2005, Blogger Tory Gattis said...

It is hard to tease apart the variables from the Census data in their Table 1. Most people would agree that Houston, Dallas, and Atlanta have been some of the most aggressive freeway-building cities in the nation, and have high job ratios to show for it. LA has not, and has a low one. NY, Chicago, and Philly focus on transit over freeways, have the longest average commute times in the nation, and have relatively low ratios - which shows that transit is not the equivalent of freeways when it comes to convenient mobility and keeping employers in the core.

DC and Boston buck the trend with transit focus and high ratios. What's the difference for them. I would argue it's the nature of their job base. Boston has the highest concentration of universities and medical institutions in the world. DC has the federal govt. Neither group re-evaluate their location based on commutes and cost of living like businesses do. SF is another one with a pretty high ratio, but Boston, DC, and SF are all odd cases of very small core cities in very large metro areas, which naturally drives up the job to resident ratio because the denominator is so small.

Detroit, with a very low 1.0 ratio, is an example of city where jobs have fled on a massive scale to the suburban cities.

Most of the other cities in the list are small enough that traffic is much less of an issue and they also tend to dominate their metro areas (proportionally not as much outside of the city limits).

At 6:54 PM, October 29, 2005, Anonymous Anonymous said...

"which shows that transit is not the equivalent of freeways when it comes to convenient mobility and keeping employers in the core."

Intuitively wouldnt one think that a higher ratio of transit, especially rail, would lead to a stronger core.

Here in Houston, I can hop on the freeway in clear lake and be in downtown or the galleria at about the same time. Out in the energy corrider in not much longer of a time. It expands my options without increasing the travel time too much. Where as, if I wanted to ride the "eventual" rail lines out to the energy corridor I wuold have to go to pearland and get on the airport line, ride all the way into the city, then ride all the way out the katy line, doubling my commute as compared to if the Energy corridor was in downtown. Thus it would seem that a large investment in transit would, should lead to a higher concentration of jobs at the focal point of the system. Normally downtown. Why do you think the data doesnt bear this out. Is it just that people dont want to ride transit and all the investment in transit instead of highways leads to more congestion which leads a larger incentive to move closer to the workers.

Also one of my thoughts as to why there would be a difference in job concentration between chicago and Houston is geography. Chicago is like a much larger city cut in half by the lake. One cannot live on the east side of Chicago, only the north, south and west. Thus if a company moves out west, they give a better commute to their employees that live in that direction without really hurting the people on the north or south sides. Whereas in Houston people live in every direction away from town, except out in the bay. So you really cant move down to clearlake cause all your employees in kingwood would be pissed. We have a little bit of this going on with all the developement on the katy and the west belt, since the east side of town is the least populated and sizable chunk of those that are there, are probably looking more towards the plants and port for work. But the lack of population on Houstons east side doesnt quite reach the scale of the lack of population on chicago's east side, so this trend wouldnt be expected to reach the point that it could in Chicago. Although I dont know enough about the development patterns in chicago to know if this is what is happening.

What do you think.

Maybe the same could hold for the other cities you say have a higher percentage of jobs in the core. I think both the dallas and atlanta regions have no or limited geographical constraints on their population locations, but I dont know about the rest of the cities that you say have lower percentages.

At 9:45 PM, October 29, 2005, Blogger Tory Gattis said...

I agree with most of your analysis about Chicago. And you have a good point about the balanced centrality of Houston - although it is slipping westward. Atlanta and Dallas are less balanced, with their focus moving steadily north for Atlanta and northwest for Dallas.

Typically, when a new company moves to a city, they find a nice suburb with good schools and affordable homes and move directly there. The employees move there too and have short commutes. This does limit their ability to hire in the future though from certain parts of the metro where the commutes would be unreasonable. In Houston, for example, it seems unrealistic for TI in Sugar Land to hire somebody from the Woodlands or Kingwood.

If new firms go directly to the burbs, that means core job growth must come from the growth of existing firms. Those firms will stay there as long as the hassle factor doesn't get too bad, but can, will, and have bit the bullet in the past and moved to the suburbs (witness Apache to the Woodlands), even at great inconvenience to some of their employees.

I couldn't tell if you were arguing that transit would shift jobs to downtown. That seems unrealistic. It may help preserve existing downtown employers, but won't attract almost any new ones. Any existing suburban employer already has almost all of their employees living nearby - why would they move downtown and triple everybody's commute?

In fact, I would argue that commuter rail would accelerate the loss of downtown employers because existing 30min nonstop 60mph HOV express bus service will be replaced with 50+ min 30-40mph commuter rail with transfers and walking. Note that NY and Chicago have the most extensive commuter rail networks in the nation but also have the longest average commute times.

Did that answer your questions?

At 10:39 PM, September 24, 2008, Anonymous Anonymous said...

all those booming southern cities may have aggresive freeway construction, but also the worst traffic imaginable. I'm from Chicago, and when I drove through Atlanta, with 7 lanes of traffic both ways, it was jammed slow! Chicago has it right on the money, with the transit system oriented around the Loop(downtown). Besides, Houston has some of the cheapest rents, compared to Chicago and New York. That probably has more to do with retaining jobs than anything.


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