The Ballot Box

A register of the machinery

Every rule set out with the country and the period it belongs to. Where the effect is disputed, the entry says so.

Entry 1.1 · Formulas

First past the post

A plurality in each district, and the well-documented consequences: manufactured majorities, a squeeze toward two parties, and large numbers of votes electing nobody.

One seat per district, a plurality suffices, and the arithmetic that follows — the seat bonus, the two-party squeeze, and the ballots that elect nobody — is unusually well documented.

Read the entry

A hand marks a checkbox on a presidential and vice presidential election ballot
Register 01 · Formulas in use

Eight ways to turn votes into seats

Each row is a rule, what the rule rewards, one legislature that uses it, and the size of the district it fills — because district magnitude does more work than the formula name suggests.

RuleWhat it rewardsIn use — chamberSeats per district
First past the post The largest single bloc in each district. Manufactures majorities from pluralities and squeezes the field toward two competitors. United Kingdom, Commons
Canada · India, Lok Sabha
1 seat
Two-round system Candidates acceptable to a second-round coalition. The bargaining happens between the rounds rather than on the paper. France, National Assembly
1 seat
Alternative vote Broad acceptability in a single seat. Lowest candidate excluded, papers transferred to the next surviving preference, repeat. Australia, House of
Representatives
1 seat
Single transferable vote Individual candidates over party lists. A quota elects; surplus above it transfers at a reduced value, so few papers are wasted. Ireland, Dáil Éireann
Malta · Australian Senate
3–5 seats
List PR — D’Hondtdivisors 1, 2, 3, 4… Larger lists. The divisor sequence gives the last seats to the parties already holding several, so the biggest list is mildly over-rewarded. Spain, Congreso
Portugal, Assembleia
varies
List PR — Sainte-Laguëdivisors 1, 3, 5, 7… Nothing in particular, which is the point. The odd divisors track proportionality more closely and hand smaller lists their first seat sooner. Norway · Sweden
(modified first divisor)
varies
Mixed-member proportional Both a local member and a proportional chamber. List seats are allocated to compensate for whatever the district results distorted. Germany, Bundestag
New Zealand, since 1996
1 + list
Parallel — uncompensated Two systems running side by side without correcting one another, so the district tier keeps its distortion in the final chamber. Japan, House of
Representatives
1 + list
“Varies” means magnitude is set district by district; the open dots in a mixed row are the compensatory list tier.Section 01 · Formulas

Three entries worth reading first

One from the paper, one from the map, one from the order paper.

Rounding is not a detail. It is where seats are actually decided.

Register 03 · Worked allocation

Same votes, seven seats, three methods

A constructed poll of 232,000 votes across four lists. Nothing about the votes changes between the three columns; only the arithmetic that converts them does.

List · votes
D’Hondt · 1, 2, 3, 4
Sainte-Laguë · 1, 3, 5, 7
Hare · largest remainder
List A100,000
3
3
3
List B80,000
3
2
2
List C30,000
1
1
1
List D22,000
0
1
1

The fourth list clears no seat under D’Hondt and takes one under both of the others; the second list pays for it. No votes moved. The divisor sequence is the whole difference, and choosing one is a policy decision made years before any ballot is printed. Divisor methods · Remainders

Register 02 · Reading a boundary
Packing
Concentrating a bloc into few districts so its surplus is wasted.
Cracking
Splitting a bloc across many districts so it is a minority in each.
Polsby-Popper
Area against a circle of equal perimeter. Punishes ragged edges hardest.
Reock
Area against the smallest enclosing circle. Barely notices raggedness.
Convex hull
How much of the shape’s shrink-wrap the district actually fills.

The three measures rank the same districts differently, and coastlines score badly under all of them. Compactness describes a shape; it does not detect intent. Compactness

Elsewhere in the register

All twenty-eight entries

Who keeps the register open

Bodies whose work touches the same levers of democratic design that our entries map.