This page
enables you to
run the program called ipdirect to
evaluate power indices using the fundamental definitions
directly. The indices computed are those that measure what Felsenthal
and Machover (1998) called Ipower (power as influence) based on
counting all
possble voting outcomes or coalitions equally.
The program computes the
following for each member:
References: Penrose
(1946), Banzhaf (1965), Coleman (1971)
The
algorithm ipdirect has the
advantage that it
is simple and gives exact values for the power indices. Its major
disadvantage is that it has exponential time complexity because the
computing time required doubles each time an extra member is added. In
practice this means that it works well for small voting bodies but is
realistically infeasible for n>30.
The web implementation here will in practice only work for voting
bodies with fewer than
26 members because of system restrictions.

Data Input for ipdirectEnter your
data in the boxes below. 