Economy Rules

[P3D]

The economy of each country is described by three numbers:
-   Population/Manpower (MP), by the million
-    Industrial Capacity, or IC
-   Build Points (BP), representing heavy factories for shipbuilding, artillery construction etc.
Colonies and metropolitan areas are counted separately.

1million population gives $1 revenue, up to the number of factories.
Over this limit their tax is reduced to 1/5.
This is to represent poor, mainly agricultural countries and colonies.

E.g. France, with a population of 40M, and 100 factories would get $40 revenue from the population.
A mainly agricultural country, like China, would have e.g. 300M but only 50 factories.
50M of the population would give you $50, but the rest 250M gives only another $50 for a total of $100.

In addition, each factory gives you another $1 revenue.Max starting factory size will be 3x population, absolute maximum is 4x.
The $1 revenue/MP is roughly equivalent of$1000 GDP/capita on a PPP (purchase-power-parity) basis, For this era this was ~$5000 for UK and US, 3500 for France, Germany, 4000 for Netherlands, and $700-1000 for delevoping regions.
We will take a ~40-million IRL industrialized country as our example, France.
France had a PPP GDP of $3500. This corresponds to 100 factories, and a half-year wartime income of $140.

Heavy build points, BP, will not contribute to revenue.
During peacetime, only 50% of the budget can be used for military, the rest must be invested in economical development  Our veterinary horse, France, e.g. must spend at least $70 on industry.
No such restrictions exist after full mobilization.

Money and BP can be carried over from one HY to another, but not from year to year.

Infrastructure
Increasing IC by one cost $75.
Economic growth was 1-2.5% in this era.

BP (Buld points/Heavy factory) cost
($300 for 1 BP)
$150 for 0.5BP - minimum increment

Maximum BP: cannot be larger than  1/4th of the IC.

Ship construction cost
To build 1000t of light displacement 1BP is needed. $ cost is the same as the BP cost. For destroyers, this increased by 25%. For submarines, $ cost is doubled.

Ship upkeep is 2.5% the purchase cost of the ship each half year. Wartime upkeep is Twice as much, 5%. Reserve fleet upkeep is one-fifth of it, 0.5%.

Research: Research cost is 1$ per turn per project. Research time is at least 4 turns. In the 4th turn success chance is 20%, raising 40% every successive half year.

Economic Infrastructure -  Guidelines for the Merchant Marine and Railways

A country can also build railway lines and merchant marine.
The cost of 1000NRT merchant marine is 0.25BP and $0.25 - the latter is paid from the economic development budget.
0,5BP and $1 can also expand railway network by 20km of heavy standard/broad gauge, 40km of light/meter-gauge or 100km narrow-gauge railway track.  This cost include the rolling stock.
The cost is financed from the economic development budget if it is economically feasible (like connecting valuable mineral deposits to the nearest port), otherwise from the military budget.

The the maximum merchant marine size is (IC+2xBP) times 50k GRT.

[Borys]

Ahoj!
Railroads, unless expressly stated otherwise, are assumed to run as in OTL. In some cases this is not important - Norman Britain, France, or continental Baltic Leage, where it may be safely assumed that there is a RR within spitting distance.
But in the colonies or less developed countries this counts.
Borys