POLS2130 · Week 2

Selectorate Theory Interactive

Explore how the selectorate, winning coalition, and loyalty norm shape governance — from kleptocracy to democracy.

The Loyalty Norm
W / S

A coalition member considering defection has only a W/S probability of making it into the challenger's new coalition. The smaller this ratio, the riskier defection is — so members stay loyal, and the leader can pay them less.

Loyalty Norm Calculator

Drag the sliders to see how the loyalty norm determines the leader's bargaining power.

$1,000M
100,000
1,000
W / S
0.010
Very loyal
Max Private / Member
$1,000,000
T / W
EU(Defect)
$10,000
(W/S) × (T/W)
Min Cost / Member
$10,000
≈ EU(Defect)
Leader's Surplus
$990M
T − W × min pay

Compare Two Societies

Same tax revenue, different selectorates — see how W/S alone changes everything.

10,000
1,000
Private Goods per Member
T / W

Leaders prefer private goods (contracts, land, tax breaks) because they create lock-in. But as the coalition W grows, each member's share T/W shrinks — until it falls below the value of public goods, and the leader must switch strategies.

Private vs. Public Goods Explorer

Watch the T/W curve cross the public goods threshold as you increase the coalition size. The chart uses a logarithmic scale so you can see both small and large values clearly.

$1,000M
1,000
$5,000

Private Goods / Member

$1,000,000
T / W = $1B / 1,000

Public Goods Value

$5,000
Per-citizen value of public goods

The Tipping Point

At what coalition size do private goods per member fall below the public goods value?

Tipping Point (W*)
200,000
T / g
Current T / W
$1,000,000
Above threshold
Dominant Strategy
Private Goods
W < W*

It's the Institutions, Not the Leader

Selectorate theory's core insight: civic-minded leaders are neither necessary nor sufficient for good governance. What matters is the institutional structure — W and W/S — not personal virtue.

Leaders Prefer

Small W, small W/S — cheap loyalty, maximum discretion, hardest to overthrow. The leader extracts a massive surplus for personal enrichment or patronage.

Coalition Members Prefer

Small W, large W/S — lavish private goods (fewer people sharing the pie) and the leader cannot easily replace them (high W/S makes defection safe).

Citizens Prefer

Large W, large W/S — this maximizes public goods provision, the only benefit those outside the coalition are likely to receive.

Scenario Explorer

Click a scenario to see what selectorate theory predicts.

Scenario A
Civic Leader, Bad Institutions
Well-intentioned leader; small W, small W/S.
Scenario B
Selfish Leader, Good Institutions
Self-interested leader; large W, large W/S.
Scenario C
Revolution Without Reform
Leader replaced but S and W unchanged.
Scenario D
Institutional Reform
Selectorate expanded, W increases.

Regime Outcome Simulator

Place a hypothetical country on the W vs. W/S grid and see the predicted governance outcome.

Small (20)
Low (0.10)

Test Your Understanding

8 questions on selectorate theory. See how well you've grasped the logic.