Hi Jonathan,
Some excellent observations, thanks for sharing.
An example of one of the underlying strengths of CTPP is that even though CTPP 2000 flow data is now 13 years old, the journey-to-work data still represents the “best available” data across the country, for use in home-based work regional travel model validation
checks. I am not referring to simple HBW trip length frequency checks (for which much smaller samples, e.g., the samples available from typical household surveys), I am talking about district-to-district checks of predicted versus observed HBW person trips
by (let’s say) 0-vehicle, 1-vehicle and 2+ vehicle socioeconomic groups. Yes, the “observed” data is getting old, but can be “fratared” with the growth rates in population and employment to be a reasonably good representation of “current year” HBW flows.
Many people think travel forecasts are way off from reality because of problems with the mode choice model and/or traffic assignment procedures, but I wonder how often the real “problem” can be traced back to trip (or activity) generation and the prediction
of the zone-to-zone person trip (or activity flow) tables!
The next “best available” dataset of home-to-work commuter trips is going to be the next available “five-year” CTPP, that is now very close to a public release. There will of course be concerns that the overall number of raw records in the new “five-year”
CTPP is a lot less than what was obtained in CTPP 2000, but all that really means, I think, is that one must be very careful to never rely on the actual TAZ-to-TAZ numbers: but still feel very confident with the prudent aggregation of TAZ-to-TAZ numbers into
locally meaningful district-to-district totals. In regards to the national sample, the new CTPP will still be a pretty huge number of records, compared to just about anything else that is not some type of “private” purchasable database. It would be a shame
if the about-to-be-released set of CTPP-based TAZ-to-TAZ flows is the last one ever produced. If the NHTS sample size could come anywhere close to the CTPP sample size, then maybe one wouldn’t need the CTPP, but that is not going to ever happen.
Ken Cervenka
FTA Office of Planning and Environment
From: ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net]
On Behalf Of Jonathan Lupton
Sent: Friday, May 17, 2013 3:36 PM
To: ctpp-news@chrispy.net
Subject: [CTPP] The Case for ACS, the Economic Census, sampling and Federal data-gathering
The loss of Census sampling (today the ACS), the Census of Agriculture, the Economic Census, etc., would be disastrous in so many ways I find it hard to believe anyone – even deeply partisan politicians – would advocate their demise. The
small gain to the Federal government’s bottom line would be undercut by huge (albeit hidden) losses to the private and public sectors. The loss would be especially acute for small businesses.
1.
There can be no serious doubt that Federal sample products leverage their cost many times over in benefits to the economy. The benefits are so widespread, and so implicit, that the burden of proof must lie on anyone attempting to undo
Federal data-gathering. And they will find no such proof.
2.
The U.S. government has, in the past, set the world standard for data-gathering. The widespread availability of free, accurate data runs hand-in-hand with upholding the standard as the world’s foremost democratic society. To surrender
the ACS and related products is not just a bad idea, it is a retreat from leadership.
3.
Answering ACS forms, or any other Federal questionnaire, is a matter of personal responsibility. To survive, democracy depends not just on the protection of personal rights; it also demands a sense of responsibility by its citizens.
4.
I have never heard of anyone going to prison, or even being fined, for failing to provide data to Census takers. Everyone knows that there are people and businesses which refuse to cooperate; the practice of non-compliance is already
tolerated. But compliance is the law, and this sets a tone of legality which allows the ACS and other projects to gather the necessary data.
5.
If the data business becomes mostly private in nature, the cost of obtaining data will largely limit its availability to large corporations that could afford to purchase it, creating another disadvantage to small businesses and business
start-ups.
6.
Here in Little Rock we host one of the country’s largest data-gathering agencies, the Acxiom Corporation. It’s an open secret that Acxiom, and other companies like it, hold vast amounts of data about just about everybody. While Census
data is protected by confidentiality laws, disturbingly intimate corporate data can be sold to the highest bidder.
7.
While the anti-census anti-government lobby argues unconvincingly about government as “Big Brother,” there is therefore another, less accountable version of “Big Brother,” existing in secret corporate data-gathering. Such data could
become the only basis for information about our society. Without Federal laws, and Executive and Congressional oversight, who could prevent this private data from being falsified? Without the credibility of ACS and related programs as a “cross-check,” false
information could be fed into the system, and could be manipulated by private power brokers.
8.
Here in Little Rock we have a small spinoff company which has used Acxiom data to attempt census-like products. Around 2009, they privately gave me a total for the state’s largest county (Pulaski) that disagreed with my careful estimates.
They ended up being high by about 7 percent, compared with the Census 2010 count that appeared a few months later. My own estimate, based on housing records, was within 1 or 2 percent. A corporate representative thought their figures were inarguably correct;
I thought their methods for counting people were flawed. Guess who was right.
9.
Data-gathering by the Census Bureau and related agencies isn’t perfect, but it has oversight through the democratic process. I’ll trust a process that’s been around since 1790 before I trust a private company that answers first to shareholders.
It is my earnest hope that the effort to kill the ACS is so blatantly foolish that it will never make it to a vote by the U.S. Congress or Senate. I ask those who keep their ear to Congress to please keep the data community well-informed
about this disturbing development.
Jonathan Lupton AICP
Research Planner
Metroplan
Little Rock, Arkansas
501-372-3300