[EM] Tideman's 'CEC' and 'CPO' methods

[Martin Harper]

Hi all.

I saw a reference to two algorithms attributed to Tideman (two unpublished
papers in 1986) - the one called 'Complete Enumeration of Coalitions' and
the other called 'Controlled Pairing of Outcomes'.

I've been trying to find either of these papers, or any reference to the
method - but so far I've turned up a blank. Possibly because both methods
are meant to be exponentially slow in the number of candidates (!)

This is all the info i have, which I quote:

"(CEC) operates by counting the number of supporters of every feasible
combination of candidates under every posible contingency with respect to
the unavailability of other candidates. This information is processed in
such a way as to allocate representatives to the most viable coalitions in
proportion to their number... (CPO makes) global rather than sequential
decisions, compairing all possible pairs of outcomes under a rule that
discounts support from voters who give higher ranks to candidates who will
be elected under either one of the two outcomes being compared than to any
of the candidates elected under only one of the outcomes being compared"

Anyone got any ideas?
Thanks,
Martin