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WARNING: Drive Slow, Given Last Year's Revenue Drop!

The results of an interesting correlation study were published in February, 2009: Local governments use traffic citations to make up for revenue shortfalls. That is, as the economy weakens, the number of traffic tickets increases!

These statistical results, published in the February (2008) issue of the Journal of Law and Economic, were based on 14 years of statistics of revenue and traffic citations from counties in North Carolina.

The researchers even got quite specific: "A One percentage point decrease in last year's local government revenue resulted in roughly a 0.32 percentage point increase in the number of traffic tickets in the following year."

And unfortunately, when revenues increased, their was no corresponding drop in traffic tickets.

Question 1: Given this past year's revenue drop of more than 20%, what should be the percentage increase in traffic tickets?

Question 2: Is the last sentence (e.g. "And unfortunately....") a signal that a strong correlation does not really exist, but rather that perhaps other intervening factors are involved?

Source: ScienceDaily, January 16, 2009