I received the following email from Bill Drissel about my “Public Choice: The Normative Core.”  Reprinted with his permission.

Dr. Caplan

The data you seek for your “normative core” is readily available in one arena: public transportation.  I follow the Anti-Planner, Randal O’Toole.  The planned benefit is number of riders.  The planned cost is usually available in dollars(of a given vintage).  The subsequent cost-overruns and consequent ridership are also available.  So every cost/benefit ratio could easily be adjusted by a “normative core adjustment”.

For example, if extensive research shows that, for public transportation, actual costs / planned costs average 2.1 and actual ridership / planned ridership average 0.40, then the normative core adjustment factor for public transportation = 5.25.  So for back-envelope calculations, the planned cost/benefit should be multiplied by 5 or so.

I have considerable acquaintance with software estimates including many that ended up in proposals and contracts.  I don’t know of a single case of software under-run (costs less than planned).  I would guess the typical over-run for routine software development at 2:1.  For difficult stuff: 5:1.  Really hard stuff like voice, face, fingerprint recognition: much higher than 5.  Development of a capable word processor with fonts and embedded images like MS Word, a single lifetime wouldn’t be enough.

I had a one-man consulting business for 45 years.  Whenever I asked a client about his over-run experience, I got a mournful story.  If I suggested he apply an experience-based multiplier, the response was always, “If we did that, we’d never get any business!”  I guess that’s the equivalent of, “Junior Professor: By that standard, government should never do anything.”

I admire the work that you and Don Boudreaux do.  I’m 87 but if I had encountered the public choice body of knowledge while I was much younger, I might have given up engineering for economics.


Warmest regards,

Bill Drissel


The Colony, TX