There have been a few recent news stories about Portland's leaf collection program. As an economist I obsess about incentives and am inclined to believe (much to the derision of other social scientists) that people's behavior is usually most easily understood through the prism of incentives. So it amuses me to see frustrated Portlanders angry with their neighbors about raking leaves into the street.
It is simple really. It costs $1 do bag your leaves and haul them to a collection point that only operates a few hours a month. However, it is free to simply rake them into the street. You are not 'supposed' to do this, but there is no law prohibiting it nor will any fies be levied. So what do you expect.
[In my defense, I may be an economist, but I try to include social responsibility in my utility function so I took two car loads of leaves to the drop-off. However, I did do a little raking of the front yard into the street as well, so I kinda am a semi-scofflaw. But my inner economist really wanted to just rake it all into the street - which shows you why undergraduates who take principles of economics end up more selfish as a result]
But I digress. Fallen leaves are clearly a public goods problem, they make the streets dangerous, clog storm sewers, etc. We could just tax trees to lessen the problem, but we like trees. Mayor-Elect Sam Adams wants the city to consider a Leaf-Tax Surcharge. Hmmm, I am not sure how you collect a special leaf tax, as this would cause people to feel more justified in raking into the street - what you don't want. As this is a general public goods problem, the city should probably start by simply not charging people to drop off their leaves and perhaps have weekly yard waste pick ups with allowances for extra bags.
In the end though, leaves will simply be a city problem that should be thought of as no different than any other street problem: city wide and something that matters to everyone. So trying to niggle with taxes and surcharges is not a good approach.