Preferences versus predictions

Dan Keshet slogged through the Project Connect (PC) data and found that if (1) West Campus is restored to the Lamar sub-corridor and (2) the future-focused criteria points are removed then Lamar and East Riverside achieve the highest scores.

Tomorrow, PC staff will be holding a ‘data dig’ to explain their methodological choices. This is laudable and provides an opportunity for some of the ‘power users’ of the Central Corridor study to follow-up with PC staff on key questions before the Central Corridor Advisory Group and City Council make decisions.

My main request for the ‘data dig’ is that they explain the predictive power of their demographic allocation methods.

Here’s why this matters: Highland made the cut on the basis of its expected future growth, which was derived by PC’s ‘demographic allocation tool’.  It is important that PC’s demographic allocation tool have a proven track record of actually figuring out where growth happens.  Otherwise, we are building transit for bodies that might not actually be there.

As discussed previously, the demographic allocation methodology is based on policy preferences (“what parcels we would like to get growth”) instead of an empiricist approach (“historical data indicates parcels with these attributes get this share of growth”).  Below is a screenshot that details the initial algorithm of the demographic allocation tool.

hs_attractiveness_methodology

This is scoring based on development preferences espoused in documents such as Austin’s comprehensive plan.  The problem that this poses for the Highland sub-corridor (and for Austin taxpayers) is that there is no document in the public domain that demonstrates this methodology actually predicts actual growth with any accuracy. The tell-tale sign in this discussion about future growth is that there are no terms in the Project Connect methodology that speak to uncertainty in the prediction (no p-values, no ‘confidence intervals’).  That’s because this isn’t a forecast based on a multivariate regression or a time series approach.  More plainly, these are not rigorous forecasts of population and employment density in the future. It’s just a parcel beauty contest.

It is possible there is a validation exercise by the different entities that have utilized this demographic allocation approach that redeems the method by demonstrating that actually predicts growth well.   If no such validation exists, however, then there is no point to including these preference scores since they become unbound from empirical reality.  If no such validation exists, it also becomes apparent that the Central Corridor Advisory Group and the City Council might be moving forward on sub-corridor selection and route evaluation with data that is touted as accurate forecasts of future employment and population density that are actually completely speculative.

About these ads
This entry was posted in Transit. Bookmark the permalink.

12 Responses to Preferences versus predictions

  1. Tim says:

    This is hard because I think there is some validity to future speculation. Just this weekend a request was sent to the ANC list for a lawyer specializing in enforcing private deed restrictions (to prevent height and mixed-use) for a neighborhood association along the Lamar corridor. We don’t know for sure that there will be increased development in Highland, but we do know there are existing, powerful NIMBYs along the Lamar alignment.

    • Julio Gonzalez Altamirano says:

      There is substantial value to forecasting. But the methods utilized in the PC rec have yet to be demonstrated to actually be reasonable future speculations.

  2. mdahmus says:

    We also know that we’re currently seeing (more) substantial VMU on the Lamar alignment despite that powerful opposition.

  3. Neighborhoods along Lamar/Guadalupe are, rightfully, concerned about increasing the density in an area where transportation and infrastructure are already woefully inadequate to deal with the current population’s needs. There’s also the issue with children. Thanks to lack of child-friendly development and land codes, there are now neighborhoods in the core with less than 10% children and downtown as a whole is only 3% children.

    Instead of working to fix infrastructure and transportation, so these neighborhoods could then reasonably accomodate the density they are fighting, certain factions at City Hall simply accuse these neighborhoods on NIMBY tactics and then use that as justification to not spending money on fixing the failing infrastructure and transportation. Meanwhile, taxpayers get the bill for new schools in the outer neighborhoods, while existing schools in the core are no longer being utilized.

    We need to quit swallowing the sound bites City Hall feeds us and start asking ourselves if the questions these neighborhoods are asking might deserve answers.

    Why isn’t new development child and family friendly? Why are bars and other adult businesses not zoned and regulated to better co-exist with neighborhoods? What can we do differently to ensure the next row of apartment complexes doesn’t just add more cars to already failing roads? How do we build apartments and other housing that will attract families with children back to neighborhoods where families are being priced out? What responsibility should a developer have when they add density to an already constrained and over-burdened corridor?

    These are the kind of questions being asked – and I think its past time we stop defending the City’s tactics to simply scream NIMBY instead of answering these neighborhoods’ questions.

    (sorry to go off topic – but the NIMBY argument needs to be exposed as a City Hall tactic that has absolutely no place in these kind of discussions)

    Mary Rudig
    editor, North Austin Community Newsletter

    http://www.lovenorthaustin.com

    • Tim says:

      Fine Mary. “Neighborhood Character Preservationists” are very powerful.

      I’ve done a massive amount of work on the facilities master plan and cheerleading urban schools. You know where kids come from in urban Austin – apartments.

      “Why isn’t new development child and family friendly?”
      Why do you assume new dense development is not? Based on where kids come from in Austin’s inner neighborhoods I’d suggest that single-family homes are not child friendly and are what should be banned from the urban core if we’re trying to encourage families. I do agree, thought that the McMansion ordinance does not allow the sort of gigantic homes that suburban families seem to want. Then again I’m not sure that people who want huge homes want to live in the urban core.

      “Why are bars and other adult businesses not zoned and regulated to better co-exist with neighborhoods? ”
      Why do you assume these are not child friendly or being close by is not an advantage?Most establishments that serve alcohol are overrun with children. Look at Central Market, Phil’s, etc. The reason I love urban Austin (and I’m guessing a lot of other people do based on being out and about) is that many of us can walk with our kids to a place where there’s a playscape and we can have a beer. That’s an urban *advantage*.

      Putting in massive numbers of units, hopefully crashing the market is really the only way to help with affordability.

      Making the Lamar/Guadalupe area look more like a suburb will just make it more un-affordable and will not increase the number of children.

    • M- says:

      Everyone should take not of the letter from Mary Rudig. These are not idle threats. Neighborhood activists in Austin have a proven track record of successfully obstructing dense urban development, will continue to do so and will continue to be given deference to by politicians – who should really ignore such nonsense. Her letter perfectly shows why NIMBYism is critical to consider in rail placement and that the city should couple a commitment to allowing for dense, mixed-use development within a 5 minute bike ride of every proposed station. Neighborhoods who fight this should not get a station – period. We should not invest one dime in taxpayer money putting stations in neighborhoods where the populace demands the preservation of SF housing in the transit corridor.

      • mdahmus says:

        Bear in mind that the neighborhoods along certain previous and current Mueller routes have been MORE obstructionist and have been MORE successful in fighting density than have the neighborhoods along Lamar and Guadalupe.

  4. Dan Keshet says:

    I don’t think you’re going to get a good answer. During the AURA data meeting with Project Connect, if I recall correctly, Project Connect (specifically Scott Gross) expressed the opinion that having accurate projections was not important, and that it was completely appropriate for projections to be aspirations rather than aspire themselves to accuracy. Obviously, I disagree wholeheartedly and believe that labeling this methodology as a “Projection” is misleading at best.

    • Dan Keshet says:

      Scott got in touch with me, understandably upset at my characterization of his comments. “Having accurate projections [is] not important” were not his words, nor are they a fair representation of his words. The context for the actual comment he made was during the AURA meeting at the Austin History Center, in which the Project team came to answer questions from the public. I asked whether the 2030 numbers were intended to be projections of what we think most likely to happen or aspirations about what we would prefer to happen*. He said that both are important goals and that the 2030 numbers blend the two goals. In personal correspondence to me, he has elaborated on that and I will post more on that later.

      There are clearly differences between approach here, but it isn’t useful for advancing the discussion for me to use flip, inaccurate summaries of others’ statements.

      Scott: I apologize.

      * “What we would prefer” here is shorthand for something like “the body politic’s preferred development path as expressed through various planning documents passed by various government bodies”, not for “what the Project team would prefer.”

  5. Pingback: A New Balance for Austin Transportation Policy | Keep Austin Wonky

  6. Pingback: Time for plan B(RT) | Keep Austin Wonky

  7. Pingback: A day late and a few thousand riders short | Keep Austin Wonky

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s