This page enables you to
calculate ShapleyShubik indices exactly using the program ssdirect which employs the
fundamental definition directly. The direct enumeration algorithm
performs a search
over all the possible voting outcomes and finds all swings for each one.
Reference: Shapley and Shubik (1954). This algorithm has the
advantages of simplicity and of giving 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 is suitable for small
weighted
voting bodies but is practically infeasible for medium sized or larger
ones.
In practice the web implementation here is not feasible if the number
of
voters exceeds about 25.

Data Input for ssdirectEnter your data in the boxes
below. 
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