I recently tweeted a Willamette Week article by Katie Shepherd that reported the fine for fare evasion on TriMet is being reduced from $175 to just $75. This reminder of the policy shift that House Bill 2777 will bring prompted me to point out that the article made no mention of an increased frequency of fare inspections.
That prompted TriMet to reply:
As they explore their options, I wonder if TriMet’s planners understand the mathematics behind this fee reduction. To merely maintain the same level of deterrence against fare evasion, TriMet will have no choice but to increase its inspection frequency.
The basic calculation is rather elementary. The strategy of fare inspecting should be to make the riders’ expected savings from fare evasion be zero. That condition is found in the following equation:
(Probability of getting caught) x (the cost of the penalty) = (price of fare)
We get an inspection rate of around 1% when we plug in the current numbers where the average fare price is $1.50 and the fine is $175:
(Rate of inspection) x $175 = $1.50
Now lower the fee to a mere $75:
(Rate of inspection) x $75 = $1.50 ⇒
(Rate of inspection) = $1.50/$75 = .02 = 2%
This drop in fine will thus essentially double the required inspection rate. That will be mighty costly. Is TriMet prepared for this? Was this tweet an oblique vow to a New Year’s resolution about getting serious about keeping the free riders from crowding out their duly paid customers?