Demonstration 1 of 4
Stationary bandit and survival horizon
When does a ruler restrain extraction and pay for a patrol?
A ruler who expects to stay values the future tax base, so restraint and public order pay. A short horizon shrinks the continuation weight and immediate extraction wins again.
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Heavy extraction yields 45 now and 15 next year; moderate extraction yields 38.5 in both years. A patrol costing 8 raises moderate revenue to 45.5. s is the ruler's survival probability and delta = 0.90 the discount factor, so next year is weighted by s x delta.
Predict first. At survival 0.20, which policy wins?
Choose an example
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Constructed example: the chapter's hypothetical district (revenues 45, 15, 38.5 and 45.5, patrol 8, delta 0.90, survival 0.85 and 0.20); survival 0.50 is added for comparison.
Calculated values
- Continuation weight
- 0.765
- Heavy
- 56.4750
- Moderate
- 67.9525
- Moderate plus patrol
- 72.3075
- Best policy
- Moderate plus patrol
Hypothetical teaching numbers, not historical data. With survival 0.85 the ruler weights next year by 0.85 x 0.90 = 0.765. Heavy extraction is worth 45 + 0.765(15) = 56.4750, moderate extraction 38.5 + 0.765(38.5) = 67.9525, and moderate extraction with the patrol 45.5 - 8 + 0.765(45.5) = 72.3075. The best policy is moderate plus patrol.
Worked steps
- Weight = 0.85 x 0.90 = 0.765
- Heavy = 45 + 0.765 x 15 = 56.4750
- Moderate = 38.5 + 0.765 x 38.5 = 67.9525
- Patrol = 45.5 - 8 + 0.765 x 45.5 = 72.3075
- Highest: Moderate plus patrol
Use the idea
When judging whether rulers will invest in order or restrain taxes, estimate their expected tenure as well as the revenue at stake.
Where the conclusion applies
Two periods, fixed revenue paths for each policy and risk neutrality; the values say nothing about whether the tax rate is socially optimal.
Check your understanding: At s = 0.20, what are the heavy and patrol values?
Chapter 79 source: section "Olson stationary-bandit model".
Demonstration 2 of 4
Voracity effect and windfall claims
How can a windfall leave less for investment than before?
When groups cannot commit to restraint, each claims more than its share because it expects the others to escalate. Total claims can exceed the windfall, crowding out investment. A binding cap on new transfers breaks the escalation.
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Normal resources are 150 dollars, committed services 60 and transfers to four blocs 45. A 30 dollar windfall W arrives and each bloc demands d more, so transfers T rise by 4d. Investment is what remains.
Predict first. Above what per-bloc demand does investment fall below 45?
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Constructed example: the chapter's hypothetical economy (150, 60, 45, windfall 30, four blocs demanding 12, proportional 30 in total, cap 18); demands of 6 and 15 are added for comparison.
Calculated values
- New claims
- 48.00
- Transfers
- 93.00
- Claim multiplier
- 1.6
- Investment
- 27.00
- Investment under the 18 cap
- 57.00
Hypothetical teaching numbers, not historical data. Each of four blocs demands 12 more, so transfers rise by 48 to 93 and the claim multiplier is 48/30 = 1.6. Investment is 180 - 60 - 93 = 27, so investment falls 18 below its pre-windfall 45: the voracity effect. A binding 18 cap keeps investment at 57.
Worked steps
- New claims = 4 x 12 = 48; transfers = 45 + 48 = 93
- Claim multiplier = 48 / 30 = 1.6
- Investment = 180 - 60 - 93 = 27
- With the 18 cap: 180 - 60 - (45 + 18) = 57
Use the idea
After a revenue windfall, compare the rise in claims with the windfall itself; a ratio above one signals voracity.
Where the conclusion applies
Fixed services, symmetric blocs and a cap that actually binds.
Check your understanding: If each bloc demands 15, what are the multiplier and investment?
Chapter 79 source: section "Voracity effect".
Demonstration 3 of 4
Extractive elite tax choice
Why can a growth-raising arrangement be politically unattractive to the elite?
The elite maximizes its own revenue, which peaks at tau = 0.5, not total output. A project that raises output mostly benefits producers, so an elite paying the full cost turns it down.
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Potential output is e0 = 160; extraction at rate tau leaves output y = e0(1 - tau), of which the elite takes R = tau y. A public input costing 8, paid by the elite, raises potential output to 180.
Predict first. Will the elite fund an 8 unit input that raises net social output by 7 at tau = 0.25?
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Constructed example: the chapter's hypothetical economy (e0 = 160, tau 0.5 and 0.25, input 8 raising e0 to 180 at tau 0.25); tau = 0.75 and the input at tau 0.5 and 0.75 are added for comparison.
Calculated values
- Output
- 80.00
- Elite revenue
- 40.00
- Producers keep
- 40.00
Hypothetical teaching numbers, not historical data. At tau = 0.50 output is 160(1 - 0.50) = 80.00, the elite takes 40.00 and producers keep 40.00. Revenue peaks where 160(1 - 2 tau) = 0, at tau = 0.5.
Worked steps
- y = 160 x (1 - 0.50) = 80.00
- R = 0.50 x 80.00 = 40.00
- Producers keep 80.00 - 40.00 = 40.00
Use the idea
When a socially productive reform stalls, compute the decisive group's private change separately from the social gain.
Where the conclusion applies
Linear output loss in the tax rate, an elite that pays the whole input cost and no change in who holds power.
Check your understanding: At tau 0.25 with the input, what is the elite's private change?
Chapter 79 source: section "Extractive Institutions".
Demonstration 4 of 4
Collection capacity and the officeholder's horizon
Why can a valuable tax-capacity project be rejected by the official who must pay for it?
The public value of better collection accrues over years, but an officeholder who may lose power counts only the part it expects to keep. Insecure tenure makes capacity building look unprofitable.
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Revenue is T = q tau B with base B = 2,000 dollars, statutory rate tau = 0.18 and collection capacity q. A 50 dollar project raises q from 0.45. Future gains are discounted by 0.92 a year over three years. p is the officeholder's probability of keeping control next year.
Predict first. At capacity 0.70, does a retention probability of 0.60 make the officeholder invest?
Choose an example
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Constructed example: the chapter's hypothetical economy (base 2,000, rate 0.18, capacity 0.45 to 0.70, cost 50, discount 0.92, retention 0.40); capacities 0.55 and 0.85 and retention 0.60 and 0.80 are added for comparison.
Calculated values
- T0
- 162.00
- T1
- 252.00
- Annual gain
- 90.00
- Present value
- 248.976
- Net of cost
- 198.976
- Officeholder benefit
- 36.00
- Officeholder
- Rejects
Hypothetical teaching numbers, not historical data. Raising collection capacity from 0.45 to 0.70 lifts revenue from 162.00 to 252.00, a gain of 90.00 a year worth 90.00 x 2.7664 = 248.976 over three years, so the project is valuable at a cost of 50. The officeholder counts only 0.40 x 90.00 = 36.00, so it rejects the project; it would need a retention probability of at least 50 / 90.00 = 0.556.
Worked steps
- T0 = 0.45 x 0.18 x 2,000 = 162.00
- T1 = 0.70 x 0.18 x 2,000 = 252.00; gain 252.00 - 162.00 = 90.00
- PV = 90.00 x (1 + 0.92 + 0.8464) = 90.00 x 2.7664 = 248.976
- Net = 248.976 - 50 = 198.976
- Officeholder: 0.40 x 90.00 = 36.00 against 50, so it rejects the project
- Break-even retention = 50 / 90.00 = 0.556
Use the idea
When state capacity stays low, compare the project's present value with the decision maker's expected private share.
Where the conclusion applies
A fixed base and rate, a three-year horizon for the social value and an officeholder who values only next year's gain; compliance and privacy costs are omitted, as in the book.
Check your understanding: At p = 0.60, does the officeholder invest?
Chapter 79 source: section "Fiscal Capacity & State Building".