Alabama Paradox

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The following consequence of seat allocation procedures, which is viewed as paradoxical , is referred to as the Alabama paradox (also mandate or seat growth paradox ): A party can lose a mandate if more mandates are to be allocated (illogical jumps) with the same election result.


To illustrate the Alabama paradox, initially 323 and then 324 mandates are distributed to four states / parties according to the Hare-Niemeyer process .

Country size Result in 323 mandates Result with 324 mandates modification
Proportional off
Seats Proportional off
A. 5670 183.141 183 183 183, 7 08 183 +1 184 +1
B. 3850 124.355 124 124 124, 7 40 124 +1 125 +1
C. 420 13, 5 66 13 +1 14th 13.608 13 13 −1
D. 60 1, 9 38 1 +1 2 1, 9 44 1 +1 2 ± 0
total 10,000 323,000 321 +2 323 324,000 321 +3 324 +1

It should be noted how the number of mandates of the state or of Party C decreases from 14 to 13. This is due to the fact that when the total number of mandates increases, the arithmetic proportionality for large states / parties increases more than for small ones. Therefore, the fractional values ​​for A and B increase more than for C, with the consequence that A and B overtake C in the fractional value, so that not only B receives the 323rd mandate, but also C loses the 324th to A.
The number of mandates is increased by one. Obviously, it can be assumed that each state can therefore claim 0.25 more mandates. This is not the case, however, because the new mandate is not distributed equally, but also based on the size of the states. This gives:
A: +0.567
B: +0.385
C: +0.042
D: +0.006

Discovery, naming

The Alabama Paradox was first discovered when calculating the population-dependent mandate claims of the individual US states in the House of Representatives based on the census in 1880 . At that time, the executive of the CW Seaton census authority calculated the new mandate distribution for the House of Representatives using the Hamilton procedure ( Hare-Niemeyer procedure ), doing this for various amounts of mandates to be distributed. He accepted values ​​between 275 and 350 mandates. He discovered that the state of Alabama receives a total of 8 seats for 299 House of Representatives and only 7 seats for 300 House of Representatives. Thereupon an agreement was reached on a number of representatives in the House of Representatives, in which the Hare-Niemeyer procedure resulted in the same distribution as the Sainte-Laguë / Schepers procedure . After the census in 1900, the Sainte-Laguë / Schepers method was finally adopted. The Hill-Huntington's disease method has been used since the 1950 census .

See also

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