[PnP] Economic Project, Part 1 (rev 2)

Burton Choinski bchoinski at verizon.net
Mon Mar 31 03:54:11 CEST 2014

Note: After playing with the numbers, in order to keep the farmer/urban ratio proper, I decided the "per season" was per-year.  re-formulated the assumptions and gave my reasonings. :) Also reformatted.

Greetings everyone!  It's been a long while since I put anything major up to the list, and given the low traffic I figured I may as well do so with a project I have been working on for what seems like several years (off and on, including endless tweaks and redos).  This is my "Economic Unification" project.

For all the years my group and I have been playing P&P, one of the largest irks we had was with the equipment list, mostly with some of the wacky prices, but also because of them it made fitting in new equipment somewhat difficult.  5 years ago, when we restarted our "Legends" campaign with their characters of 25 years ago, one of their goals was to eventually carve out a kingdom for themselves (which they have, in the "unclaimed" hills and mountains of the western elder mountains, close to Treaus.

Well, once you get such a kingdom, they needed to know what they were bringing in with regards to taxes.  I could have gone with the culture book's GNI calculation and been done with it, but being the type who likes to crunch numbers and lay out a consistent basis for things, I went back to our old nemesis, the equipment list and how things are priced.  To do this I would need to work out costs from the ground up, thus the birth of this project.

I am presenting these series of posts as both a presentation of my ideas to the list as well as draw upon the collective experiences of GM's and players alike to poke holes at my assumptions, shore up faulty logic, or add missing information that would make it more complete.  I hope the eventual "laws" that are generated can then be used by all to create a more comprehensive and logically consistent set of prices for any gear or services we ever need.

Now, I am not an economist (though some of you out there may be), so I'm looking at these rules as a step-by-step system to lay out a logical reasoning for the values of various goods and services.  The goal is not to make "Sim-Donara", and may of the assumptions are made to reduce the laws to a bare minimum with a "perfect world" mindset, with the assumption that once we have a solid foundation, simple modifiers can then be worked up to reflect the variances one might encounter in the actual game world.

In summation, before I begin, I plan to present my thesis for open use as I plan to use it in my game.  Comments pointing out missing parts or faulty logic are certainly welcome, and I will try to reply to all with my reasons why I don't think they work or with updated info as needed once integrated.  I have a large excel spreadsheet that is backing all these calculations, and I'll happily email it to anyone who wishes a copy at any point (I'll have to keep it revisioned, as it may get updated a lot depending on responses).  Simply contact me at bchoinskI at verizon.net and ask for the economic sheet.  And if you find bad formulas, let me know!

With luck, at the end of this a comprehensive an internally consistent equipment and services list can be created.


The following base assumptions are used as the core of the system:
   * A P&P year is 360 days; a P&P week is 6 days, for 5 weeks per month
   * A P&P ton is 2000 pounds
   * Normal definitions of an acre (43,560 square feet) and mile (5,280 feet)
     apply; a square mile contain 640 acres
   * Yields and production rates based on real-world data for Roman era thru
     Middle-Ages, where I could find it; Some info drawn from GURPS Low Tech
     sources since I believe the authors have tried to do the same research
     I am doing and probably had paid access to sources I can't google up
     (Assuming GURPS TL1 or TL2 for the P&P world, with TL3 in some cultures
     for specific technologies)
   * All occupations are averaged out to the productivity of a single man;
     yes, many occupations are performed by teams of men, but we average it
     out to find a single man value.  This allows us to easily calculate the
     production of any number of people.
        - For simplicity, children (who normally contribute to a family's
          income) produce at HALF rate, but likewise require HALF the needs.
   * We assume an average food need for human adults of 2.5 food points
   * Values of products or services are largely based on the cost of labor,
     plus any source materials for refining or crafting occupations
   * When sources refer to a "family", we assume two adults at full production
     one youth at half production and two children at quarter production and
     perhaps a baby at no production.  Thus, a family of 5-6 has the production
    (and income needs) of 3 adults.

All occupations have a set standard of living, defined as a specified number of bits per day.  The base values by station at based on the P&P starting wealth table and some ideas from other games:
   * Station 1 -- Labor (1bb), Skilled Labor (2bb)
   * Station 2 -- Crafter (5bb), Master Crafter (10bb), Tradesman (5bb),
                  Uncommon Tradesman (10bb), Pack Trader (5bb),
                  Minor Merchant (10bb)
   * Station 3 -- Artisan (20bb), Master Artisan (50bb), Merchant (20bb),
                  Master Merchant (50bb)
   * Station 4 -- Specialist (100b), Rare Specialist (200b)

The foundation of most civilized lands is agriculture.  Farmers at Station 1 make up the majority of the population, and the overall cost of food is based on what their income is worth.

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FARMER (1bb/day)
GURPS Low Tech Companion #3 (henceforth GLTC3) states that barley produces 705# per acre per growing season, with wheat producing 355# and legumes 280#. Agriculture at the level of technology produces yields 4:1 (4 pounds of grain for every pound sewn). I am unable to nail down a distinct maximum amount of land that a farming family can manage per year, but we want to match a more "ancient" rate of support needing plenty of farmers to support an urban population.  Analysis of the P&P cultures shows that the weighted average margin is 20% (i.e. 1 farmer can support 1.2 people).  Iteration of various values in excel indicates that the average farmland that a family can manage is 14 acres.  At the P&P level of technology, the two-field system is most likely used, so half of this land is left fallow fallow each year to prevent soil exhaustion.

With the above numbers, a farm produces 4,935# of barley, 2,485# of wheat or 1,960# of legumes each year, of which 1 part in 4 must be retained for next years crops.  This results in usable returns of 3,702# of barley (1,234#/adult), 1,864# of wheat (622#/adult) and 1,470# of legumes (490#/adult). Wheat produces about 1.7x the weight of the grain in straw (usable for fodder), or 4,225# (1,409#/adult).  To keep things simple, barley produces less usable fodder, keeping it's yield at the same level as wheat.

A farmer works 300 days a year on his own farm, spending an additional 30 days (tithe) working the lands of his liege lord.  The remaining 30 days in the year account for sickness, holy days or bad weather, but implies that a farmer could work those days, getting +10% income.  The 300 days working his own farm must meet his income needs (1bb/day), so we can determine the value of the crops. It is assumed that grains make up 75% of the income, with straw/fodder making up the other 25%.  Legumes make up 100% of the income when grown.
	Barley/Oats  -> 0.1824bb/# (9b for a 50# bushel)
	Wheat        -> 0.3618bb/# (18b for a 50# bushel)
	Legumes      -> 0.6123bb/# (30b for a 50# bushel)
	Fodder       -> 0.0533bb/# (11b for a 200# bale)

GLTC3 states that an active adult requires 750# of grain per year to survive. Wheat provides more protein than barley and is used for bread, with legumes making up the remainder of the needed protein (meat was relatively rare). Working the numbers such that food costs 2/3 the income, the diet is 70% barley, 20% wheat and 10% legumes, the yearly food cost is 196bb/year. Obviously, lower quality food can be bought for less if he needs money for other things.

In terms of population support, using the same percentages to determine the average food cost, a single adult farmer produces enough to feed 1.383 adults.  While higher than the P&P weighted margin, it is enough to cover some high ratio cultures without the need for serious food imports (i.e. A'Korchu at a 33% margin or Dirlla at a 37% margin).

Given the above, the average adult requires 2.5FP per day, or 900FP per year. A grain/legumes diet provides 1.2FP per pound.  At least now a Station person can afford his food (Book 1 had grain at 2bb per pound!)

The value of cropland works out to the income produced by the people working it for you.  At 300b income over 14  acres, this comes to 21.43bb/acre for farmland (active+fallow).  Book 1 states that farmland is worth 1SC per acre when purchased, so if we go with this value as one of our "data anchors" this implies that land sells for 4.7x it's yearly production income.  This will come in handy when we eventually determine the cost of other land.

The cost of wintering a horse is based on 100 days where grazing is not possible. For a 1000lb horse, this is 20# of straw fodder per day, or 1SC per year.  Working horses (horses on the battlefield or constantly working) cannot graze and will need oats as a supplement (0.5lb oats per 100lb weight) in addition to purchased straw, so owning a horse will cost an adventurer 12bb per week while traveling (6CC per month).

BREWER (5bb/year)
On old resource I've mined for info is "Economy Quest", a set of economic rules made for Runequest (available if desired, contact me by email). From their rules:
	Brewers are crafters living in the 1440 p. income bracket. A small brewery
	produces 2900 liters of ale per year. This ale sells, in bulk, for 5 clacs
	per liter. A brewery may grow its own hops, requiring a small farm to do
	so, or buy them, which costs 220 pennies per year.

The 1440p income is the same as our 5bb/year. 2900 liters is roughly 766 gallons.  Scaled down from a family, this averages to 256 gallons per adult. From personal experience and online sources, a good rule of thumb is 10# of malted grain for 5 gallons of water, or 2# per gallon. While hops were not introduced in the real world until the middle ages, other herbs or spices were used as preservatives.  We assume the brewing family grows whatever was used on their own lands and gathers their firewood for boiling the brew.

(NOTE: Is this too little beer?  I have brewed in the past, in 5 gallon batches and it took me, with modern gear a few hours to boil and cool the wort, followed by a week or so of fermentation before bottling.  Were I to do this every night (had I the equipment) for 300 days I could do about 1,500 gallons a year If I also had to spend the day gathering firewood, picking hops, checking on the grain being malted for the next batch, etc. And that's with  20th century appliances and modern plumbing.  If I had to do it with firewood and getting water from the local well, I could easily see my rate cut in half.)

At 5bb per day, the 300 day rate is 1500bb. Instead of working a liege-lord's lands, the brewer pays an additional 10% of their income in beer to the lord, so he must actually produce 1650bb of value in those 300 days (which allows for +20% income if he works extra days). Given the cost of 500lb of barley, plus his income needs and tithed value we can determine the value of his beer or ale.
	Beer	  -> 6.965bb/gallon

The brewer would likely sell his beer in 10 gallon lots (you supply the barrel; the actual cost of a barrel lies in a future installment), cleaned up for "processing and handling".
	Beer	->  7CC per 10 gallon keg

TAVERN-KEEPER (5bb/year)
With the cost of beer from his supplier at 7bb/gallon, and a noted Book 1 cost of 2bb per quart (8bb/gallon), a Tavern-Keeper's markup is obviously 1bb per gallon (15%), meaning he must sell 1,650 gallons a year (about 5.5 gallons per day, over 300 days of operation). Using this same ratio, a tavern that sold prepared food would use the same margin
	Beer or Ale	-> 2bb/quart, 1bb/pint
	Watered Ale -> 1bb/quart
	Tavern Meal -> 1/4bb per food point (per day) at Station 1

Web sources:

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