Post hoc ergo propter hoc

Post hoc ergo propter hoc - it's a fallacy, logically speaking...a technical flaw which makes an argument unsound or invalid.

The fallacy of Post Hoc Ergo Propter Hoc occurs when something is assumed to be the cause of an event merely because it happened before that event. For example: "The Soviet Union collapsed after instituting state atheism. Therefore we must avoid atheism for the same reasons."

Most people will see that these two issues, state atheism and the fall of the Soviet Union, are not causational. The practice of atheism did not, solely, result in the fall of the USSR.

Another example of this would be: "Maggie Thurber was elected County Commissioner and since that time, unemployment in Lucas County has declined." No one, including me, would say that my election caused the unemployment rate in the county to fall. But we seem to accept this fallacy when it comes to other issues.

Why do I raise this point? It's because of the false belief that building an arena will result in an economic boom in this area, simply because other communities who've built arenas have seen improvements. Today's Blade article on last night's arena public forum starts with this:

"Until the arena came along, the business core of Grand Rapids, Mich., struggled. Storefronts were boarded up.

Today, 10 years after the Van Andel Arena was built, the mid-sized city in western Michigan claims that it's competing with Detroit.

That was the comment Richard MacKeigan, general manager of Grand Rapids' Van Andel Arena, had for a public hearing last night on Lucas County's proposed arena.

Mr. MacKeigan, who works for SMG, a national arena operator based in Philadelphia, which is bidding to be the Toledo arena operator, said Toledo would have a similar experience."

To suggest that the Van Andel Arena (opened in October 1996) is the reason that storefronts are no longer boarded up is a prime example of the post hoc ergo propter hoc fallacy. It ignores other such factors whose impact is signficantly greater than the building of arena - factors like educational level of the workforce, tax rates, sales taxes, population, per capita income, business climate, etc.

Just compare the census date of Grand Rapids to Toledo. You'll see that, from 1990 to 2000, GR had a population increase of 4.3% while Toledo's population decreased 5.8%. Almost 28% of GR's population has a bachelor's degree or higher compared to Toledo's rate of 16.8%. Median household income in Grand Rapids is about $5,000 higher than Toledo's. Toledo has 17.9% of its population below the poverty level compared to GR's rate of 15.7% Retail sales per capita in GR are about $2,000 more than in Toledo.

When you get to County data, some of the figures are even more disparate. Kent County's population increased 14.7% from 1990-2000 while Lucas County's population declined 1.6%. Kent's median household income in 2003 was about $7,000 more than in Lucas.

Additionally, the hotel-motel taxes in Grand Rapids are, according to the gentleman from last night, 12% versus our current rate of 14.75%.

But the arena is not the only area in which such fallacious arguments are used...just look at the rationale regarding the recently-passed minimum wage hike. Policy Matters Ohio used a study from the Economic Policy Institute which said that states which raised the minimum wage didn't see a decline in employment. Again, this argument presumes that no other factors contributed to the employment situation - and declines to consider whether or not employment might have increased by MORE than it did had there not been a hike in a minimum wage.

There's a lot of debate we can have on such issues and policies. But if we want to improve the quality of our debate, we must be capable of spotting invalid arguments and rejecting them - otherwise, we'll find ourselves facing the consequences of bad decisions.