Bitcoin Universe · Model 13

The monetary systems machine

Two machines for creating money, side by side on one timeline. On the left, a simplified fiat system where people choose the growth rate. On the right, Bitcoin's fixed issuance schedule. In front of each, a gauge for prices, which is not the same thing as the amount of money.

Hypothetical scenarios · Bitcoin supply from the real schedule

Year

Left machine
Fiat: the handwheel hypothetical

Money supply growth How fast the amount of money grows each year. A decision, not a law of nature: it can be changed at any time.

Real output growth How fast the economy produces more goods and services. Change in velocity Whether money changes hands more often (+) or less often (−) each year.

Right machine
Bitcoin: the sealed schedule

There is no handwheel: issuance follows the block subsidy rule that every full node checks. Changing it would require users to run different software.

Demand to hold bitcoin A pure assumption about adoption and saving. It can rise or fall, and it moves the right-hand price gauge.

Scenarios hypothetical

Two rulebooks

Money supply is not prices.

Side by side

Compare outcomes in hypothetical

Scenario	Fiat supply	Fiat prices	BTC supply	Prices in BTC	Assumptions

Every value is relative to 2012 (×1). Bitcoin's supply column is the same in every row because its schedule does not depend on the scenario; its price column changes because purchasing power depends on demand. Bitcoin's price-level and purchasing-power rows are scenarios: for past years they are a counterfactual under the assumed demand, not what happened.

Money in each tank, the gauge needles and the timeline carriage Hypothetical scenario values

The fiat machine is a teaching simplification, not a model of any real currency or central bank: real money is created mostly through bank lending and central bank operations, at rates that change, and policy aims such as stable prices or employment are not shown. Neither machine is presented as better. A fixed schedule makes supply predictable but cannot respond to changes in demand; a policy rate can respond but depends on decisions. Bitcoin's supply uses the real subsidy rule; past dates are interpolated between real halving dates and future dates assume 10-minute blocks. Every price level is what the equation of exchange implies under the assumptions shown, not a forecast or a measurement.