World View

World View | What the Netherlands Metro Taught Me about Crime

On Dutch trams, it seems, cheating the fare system would pay. Why are riders so honest?

By Paul Raines

January 03, 2008 — CSO — I get a first-hand look at how well deterrence theory works when I board the trams here in the Netherlands--“trammin” as the Dutch affectionately call it. The Dutch metro system relies on a person buying a tram ticket beforehand and then being honest enough to stamp the ticket at a machine located on the tram. This system is largely left up to the honesty of the passengers, and what little enforcement there is comes in the way of assigned tram inspectors occasionally boarding the tram and checking that all of the passengers have stamped tickets. If a passenger is caught without a ticket, then he is fined on the spot for about 40 euros. In contrast, in the previous city I worked, New York, there were technical controls to prevent one from cheating--that is, you had to insert your metro ticket into a turnstile before the turnstile would open and allow you into the system of subway tracks.

It being the holidays, I had some idle brainpower to waste, and I wondered, does the voluntary Dutch tram system work better than the enforced system of the New York subway? It seemed to me at first that it all boiled down to the expected loss on the part of the passenger. If a tram passenger was always honest, then they could expect to pay on average about 1.50 euros per tram ride. If they didn’t buy a ticket then there would be some probability that they could get caught by a surprise inspection and would have to pay the 40 euro fine. Based on the totally unscientific technique of my personal experience and a little wild-assed guessing, I would say that the ticket inspectors board the tram once every 25 rides or about 4 percent of the time. Thus, the equation for calculating the expected loss of never paying but being occasionally caught would be the following:

E(loss) = 40 euros (if caught) * .04 (probability of getting caught per ride)
= 1.60 Euro per ride

In other words, based on expected loss it made little difference to the passengers whether they paid or not. If they were always honest and paid, then they would lose 1.50 euros per tram ride, whereas if they never paid and took their chances with being caught then they would pay, on average, 1.60 euros per tram ride. And the last calculation took no account of