I was recently in Copenhagen as a tourist, taking one of the little tour boats around the canal, and the tour guide explained these nice kayaks which you can get for free if you return having picked up some garbage from the canal. According to him, this actually has been too successful as there now isn't much trash available to be found in the canal anymore, so the kayaks have become less popular. An interesting example of perverse incentives?
Not perverse; that incentive seems to have worked as expected. If they're running out of trash to pick out of the canal, they could expand the program to include sidewalk or other trash.
(The "perverse" variant would be people dumping garbage into the canal to earn free kayak rides, similar to the "Cobra Effect" story.)
Must incentives exists in perpetuity? I would say the next course of action is come up with incentives for the next thing that needs incentivizing. Once that's done, move on to the next, so on and so forth. If there's a lapse and now there's a lot of trash again, restore the original incentives, etc.
I’m still not really getting used to the whole theme of engagement hacking comments but great example of using the Streisand effect to boost replies on your comment by incorrectly labeling it a. Perverse incentive. Bravo.
There’s a group I join and donate to who are “River Keepers” for our area. There’s quarterly kayaking/canoeing trips to clean up the river. On our last outing we collected 32.5 tons of trash.
It would be interesting to do something similar. A free kayak rental if you pick up trash.
