Alabama paradox

From electowiki
Wikipedia has an article on:

The Alabama Paradox refers to the pathological scenario of the Hamilton method in which an increase in the total number of seats in the legislature would cause an electoral district or political party to lose a seat. It is an example of House monotonicity failure and can be understood through the Balinski–Young theorem.

For example:

Party Votes
A 56.7%
B 38.5%
C 4.2%
D 0.6%

With 323 seats, the Hamilton method gives:

Party Quotas Seats
A 183.141 183
B 124.355 124
C 13.566 14
D 1.938 2

But with 324 seats:

Party Quotas Seats
A 183.708 184
B 124.740 125
C 13.608 13
D 1.944 2

The Alabama Paradox is named after the 1880 observation by U.S. census clerk C.W. Seaton that the state of Alabama would lose one of its 8 seats in the House of Representatives if the size of the House were increased from 299 to 300.