Er, pollution can affect the entire world as a whole (think global warming), and making the entire world the property of one person wouldn't be a very good idea, so methinks pollution is still a good example. Another is education. The graduate benefits from his education, but so do many other people; indeed, society as a whole benefits. Same with health care.crystal said:Would you mention an example of externatilities or transactions affecting third parties? Many people would now mention pollution as an example of externatilities. But I would argue that the problem could be solved by privatizing publicly owned areas, so that the polluter is forced to internalize all the costs.
And do you not believe in the tragedy of the commons? Keep in mind that certain "commons" (public goods) can't be made private, examples being national defense and the legal system. Others could be made private but with much difficulty, e.g. public roads.