MM wrote:

Where I live the sewage treatment plant recently broke down and needed
a new pump. Householders each had to pay a relatively small sum of
money in order to avoid tapping into the contingency fund which is
really there for replacing the entire plant in 20 years' time.

And then a number of residents refused to pay, for whatever reason I
don't know. Those who had paid got their money back and the bill for
the new pump plus labour etc was paid from the contingency fund
instead.

And therein lies the truth. Given any random bunch of neighbours, a non
trivial percentage will be tightwads.

The only way I would entertain such a "system" is that everyone pays a tiny
monthy fee into a fund in a legally watertight way that means non payers can
quickly be dealt with.

If there's ever a significant operational surplus, pay everyone back a
"bonus".

--
Tim Watts