24 October 2011

Who are we and how did we get here?

The time immediately after the decennial census is filled with wonder and renewed uncertainty. One of the prime objectives of the census is redistricting, and the various maps generated at different levels of government have occupied many a blog post here in Howard County.  One other byproduct of the Census is it helps us gain a greater understanding of our larger community.  It can be used as a type of ruler, marking data at discrete times to show trends.  It can also be used as a mirror, reflecting the various characteristics that make up the community.

It is in this spirit that I have been doing some digging.  The U.S. Census Bureau released a trove of local 2010 Census data last August.  Given the data found at the Bureau, I went on to the Maryland Department of Planning to compliment the data released in August.  What follows here is my attempt at reconciling how Howard County has evolved since 1970.


Area of Agreement



The graph above shows Howard County total population from 1970 – 2010.  Clearly, we have a lot more people here than we did in 1970.  As far as the characteristic of the line, it is a near linear positive upward curve with an approximate slope of 5800.  That is, averaged over the last forty years, Howard County has added approximately 5800 people per year.

Constituent Populations – How do you slice a pie that keeps getting bigger?

Where things get somewhat sticky is how the age-related Census data is broken down.  Although completely anecdotal, I have heard at more-than-a-few public meetings various iterations of “Howard County is Aging Rapidly” (“there are as many residents over 65 as there are children in Howard County,” “sixty is the new forty,” among others).  Conversely, as a parent of a school-age child (and one younger), I tend to keep an eye on school capacity, and those numbers are not declining.  The reality is that all age groups have seen a dramatic increase over the last forty years.

Therefore, having no clear guidance on grouping of ages, I have (admittedly arbitrarily, but with a bent toward evenhandedness) collected Howard County population age groups by twenty-year increments (0-19, 20-39, 40-59, 60-79, and 80+).  In addition, I also ascribed loose labels to each age group (youth, young adult, middle aged, senior, and meta-senior).  Although the individual reader may take exception to the referenced labels contained herein, please keep in mind that these are the best I could come up with, and I am more than willing to entertain alternate naming standards.

The grouping of the Howard County population constituent age groups are depicted below both graphically and in tabular form.



Description by Decade

In 1970, the youth component is the dominant constituent in Howard County.  Over 4 out of 10 Howard County residents is under the age of twenty.  Young adults and the middle aged combine to make up half the county population and the seniors and meta-seniors collectively represent 8% of the county.

During the 1970’s all Howard County age groups see population increases.  By 1980, the youth age group is overtaken by the young adults.  The youth percentage share has decreased from 1-in-4 to 1-in-3 and the young adult constituent alone makes up nearly 37% of the population.  Meanwhile, the middle aged, senior, and meta-senior constituents all more than double in size, but maintain hold their percentage of population (within 1%) of 28%, 7% and 1% respectively.

By the end of the 1980’s most of Columbia was built out and areas in western Ellicott City were seeing dramatic development (Turf Valley, Centennial Lane area, etc).  Youth population grows at almost the same pace as during the 1970’s; however, the young adult constituent maintains its growth pace (at twice the growth rate of the youth constituent), and the middle aged population growth rate accelerates.  So by 1990, the youth dominance retreats to about 28% of the total population, the young adult constituent gains a percentage point (now 37% of the total population) and the middle aged surge to now represent 1-in-4 people.  Seniors almost double in population and meta-seniors also double, maintaining their 7% and 1% shares of the population, respectively.

In the 1990’s, growth expands along MD-103 and Montgomery Road corridors.  River Hill development is underway.  Waverly blossoms to the north.  Middle aged growth rate (avg=2673 persons/year) bests the middle aged growth rate from the 1980’s (avg=2,230 persons/year).  Youth population increases at a faster rate during the 1990’s than the previous two decades, while young adult population growth rate slows to a trickle, adding 2,401 persons for the entire decade.

The behavior of these three population constituents during the 1990’s culminated in the great Howard County population confluence.  In the year 2000, according to the United States Census Bureau, the youth (74,085), young adult (72,673) and middle aged (74,478) population constituents all were within 1.5% of each other.

Also during the 1990’s, the Howard County senior population fell off the “doubling every decade” curve, but did add more persons during the decade (7,551) than during the 1980’s (6,079) and as a result increase their percent share of total Howard County population from just under 8% to 9%.  Meta-seniors continue to double their population during the decade and stand 4,570 strong.

In the ‘00’s Maple Lawn is in full swing.  Senior housing becomes an industry in Howard County.  Infill development comes to the county.  During the 1st half of the decade, real property values (and corresponding housing prices) soar.  By the end of the decade, a “correction” is underway.  From the population convergence, the youth and middle aged population constituents continued to increase in size, although at a slower rate.  The young adult population posted a slight negative growth, started the decade at 72,673 and ending at 69,804.  The senior population increases significantly, from 22,036 to 38,032.  This represents the 2nd largest growth for the decade (middle age increase was larger).  Seniors now represent 13% of the Howard County population.  Meta-seniors also increase in size to 6,606 persons.

Initial Conclusion

For all the numbers over the decades, the key question here is what does it all mean?  For the most part, the youth, middle aged, and meta-senior constituents have near-linear growth characteristics (although at different slopes) during the last forty years.  With respect to young adults and seniors, both constituents demonstrate linear behavior over the first twenty years.  After 1990, the young adult constituent growth is characterized by a concave down curve, while the senior population constituent is concave up.


The rationale behind the young adult and senior constituent behavior is less than clear.  As far as I know, only speculative theories and hypotheses exist.  It is a certainty that the construction of age restricted (55+) housing escalated with the introduction of the Adequate Public Facilities Ordinance (APFO) in the early 1990’s and has progressed over the last twenty years.  The shear bulk of the aging boomer generation also plays a part.  Another popular theory is that the younger generations consciously choose the urban setting of the big cities in the region and hold low regard for the single family lots and cul-de-sacs that dominate much of Howard County’s housing stock.  Lastly the economic booms and busts over the last two decades must be taken into consideration with respect to both seniors choosing to “age in place” and available housing options (and the ability to secure financing for said housing) for young adults.

As depicted in the graphs above, the Howard County age demographic trends are fairly clear and provide a basis for further analysis; however, the data is missing an important aspect.  This aspect is imbedded in the evolution of norms over time and the changing characteristics that accompany youth, mid-age and retirement.  Much as it is difficult to discern how well Sandy Koufax would pitch against Albert Pujols or Red Auerbach’s nine NBA coaching championships to Phil Jackson’s eleven NBA coaching championships; the young adults of the 1970’s were in many ways different than the young adults of today.  As they say in the world of sports – “they are of different eras,” and that aspect cannot be conveyed by simple classification of age groups.  Indeed, age groups serve as static markers that are scalar by nature.  They depict a magnitude, but provide no indication of direction.

In the near future, I will provide an alternative analysis of Howard County population growth over the last forty years.  Stay tuned.

hocoblogs@@@

1 comment:

Frank Hecker said...

Bill, this is great stuff. Thanks for doing the hard work to gather, present, and analyze this data.