Economics - General

How to make your city clean like Tokyo

I just recently returned from my honeymoon in Tokyo, Japan and Bali, Indonesia.  One thing anyone visitng Tokyo will notice is that it is very clean .  Further, Japan has the most advanced toilets in the world.  On the other hand, most Balinese burn their trash.  Why is Tokyo so clean when other world cities are not? 

Let us assume that the average cleanliness of a city equals:

  • C=100-L/S

The variables above represent (C)leanliness, (L)ittering and street (S)weeping.  The maximum cleanliness level is 100. We can see that there are two ways that a society can have clean streets. 

  1. Reduce littering.  It is possible that different societies have different preferences for the amount of littering they will do.  Japan is a fairly formal culture individuals may go out of their way not to offend anyone by littering; or individuals may just have a natural affinity for cleanliness.
  2. Increase street sweeping frequency.  For any given level of littering, more frequent street sweeping will result in a cleaner society.

If a poilcy maker has a goal to increase cleanliness in an area, how best should they accomplish this?  Let assume the following cost function:

  • c=f(L0-L)+g(S)

Decreasing littering involves some cost.  Likely, the cost of decreasing littering exhibits decreasing returns.  Similarly, there are decreasing returns from increased street sweeping.  Everyone knows that vaccuuming your house twice per week doesn’t quite make a room twice as clean as vaccuuming only once per week would have. 

Thus, we are left with the old dilemma of prevention versus treatment.  “Preventing” littering involves educating individuals and convincing them not to litter in the first place.  “Treating” littering simply involves cleaning up the littering after it takes place.  I predict that preventing littering is a more cost effective alternative for all but the lowest cleanliness levels.

Regardless of how the Japanese do it, Japan is clean.


  1. Isn’t there also a factor about modeling social behaviour? Maybe by doing a lot of “invisible” cleaning, you transmit a message to people that it is not OK to litter. Say, if you kept the street littered, people would just keep on littering because it really doesn’t make a difference… But in Tokyo, you don’t want to be the first “litterer”.

    How can you include that in a “cleanliness” formula?

  2. Welcome back, and congratulations on your marriage and globe trotting honeymoon. Hopefully, you missed all the rancourousness around the massive misinformation that has been posturing itself as health care reform debate. I’ve been missing your insightful posts here and look forward to following the discussion, if we can call it that, through your observations.

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