Conversation

Interesting argument against the idea that Market Forces Will Provide: public sanitation.
More people in the world have mobile phones than flushing toilets: because when you buy a phone you get the benefit; but with sanitation the benefit is to the community.
Historically no-one would pay for London's sewers; it took an act of parliament, which only passed because it sat next to the Thames, "The Great Stink"…
From an ep. of Tim Harford's "50 Things…": http://www.bbc.co.uk/programmes/w3csv3gp