Wednesday, March 20, 2013

Marion County Population - Is it Up or Down?

So, what happens when the Indy Star runs two population shift articles in two days?  The first says the population in Indiana and Marion County grew in 2011-2012.  The second cited a Ball State study that said more people moved out of Marion County than moved in during the three 1-year periods, 2000-2001, 2006-2007 and 2009-2010.  Well, it seems that many people will just lament the loss of Marion County population and call for all sorts of remedies.

I located the Ball State study, authored by Dabney Faulk, Director of Research, Center for Business and Economic Research.  A couple of statements caught my eye and may suggest we look more closely at the take-home message of his study:
According to the US Census Bureau, the population of
Indiana between 2000 and 2010 grew by more than 400,000
people due to natural increase and migration.
Indiana’s overall net migration was negative in 2000-2001 (-4,113) and again in 2009-2010 (-6,763). However, in the pre-recession time period of 2006-2007, net migration was positive at 2,594.
If you look at the three 1-year time periods, Indiana lost population, but within the entire decade, actually gained 400,000 real people.  Hmmm....  Just how can that be?

One caveat of the study is laid out by Dr. Faulk quite early.
With the use of IRS data, there are cases that lead to migration flows being undercounted or overcounted. First, households of the poor and elderly may not be required to file a tax return. This results in undercounting this portion of the population. Next, the migration flow data requires back-to-back years of tax returns to match up. When there are mismatches of returns resulting from marriage, divorce, or foreign in-migration, these numbers are not counted in the migration flows. This results in undercounting. Undercounting also occurs when the mailing address on the tax return is in a different county than the home address.
It seems this migration pattern may have its uses, but it also has some limitations.  Anyone who does file a tax return, (the poor, the elderly, the youth) are not counted by this methodology.  So, what are we left with?  If the three 1-year periods are suggestive of population loss in the State when we know there was actually growth in the decade, what are we to make of the suggestion of population loss in Marion County?

We have to look at the census data.

The US Census estimates that between April 1, 2010, and July 1, 2012, Marion County population grew by 1.7% (from 903,393 to 918,977).  In fact, the Census estimates Marion County grew between 2010 and 2011, too.

According to Census data recorded on the Indy.Gov site, Marion County grew 5% in the first decade of this century (from 860,454 to 903,393).

So, bottom line, Marion County is not losing population.  So, lets stop with using population loss to boost pet 'remedies'.

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