Friday 13 April 2012

Winter is coming. Where are the storehouses?

Season One Game of Thrones was excellent. But where the hell are the storehouses?

You've hereditary Lords with reasonably long time horizons, at least for the major houses. If winter is of variable duration with a fat right tail to the distribution, and winter occurs after long and variable lags, and the duration of winter is proportionate to the time since the last winter, you'd expect a few things.

Suppose that you expect a year of winter for every year of summer. You'd then be wanting to put away half your crop, every year, for the coming year if food preservation is perfect. In Season 1, it had been about sixty 10 years since the last winter*. There should be storehouses everywhere. Maybe they're all off-camera.

Now, relax the perfect food preservation assumption. In that case, there will be some maximum storage capacity beyond which any further storage is pointless. But in that world, nobody's eating fresh meat: you're eating salted preserved meats, canned fruits, and pickled vegetables coming out of storage because they're hitting their use-by date and replacing the larder with fresh.

Now, maybe summer game and produce is just so plentiful relative to population that we can just throw out anything hitting it's use-by date and replace with fresh without affecting current consumption. But we'd still expect to see lots of smokehouses and storehouses. And, we'd especially expect to see it up near The Wall.

So, why might we not see tons of storehouses?

Maybe everybody migrates south when winter comes. But that's inconsistent with the nursemaid's story about mothers smothering their infants to keep them from starving in the last long winter. And, we'd then expect to see some storehouses in the South for the periodic influx of winter-refugees.

Maybe storage is too risky: if the King can't credibly commit not to predate on the Lords' stores come winter, they won't store food. But that seems nonsensical: the King would then just tax the Lords' current production and run the storage himself.

Or, maybe civil wars are almost certain to happen in any long summer period and burning the storehouses is too common a strategy to make storage worthwhile. You can imagine conventions against this, like conventions against killing Red Cross workers, but any Lord expecting to be on the losing side likely expects to die anyway so there's no margin in not burning the other side's stores. But wouldn't we then still expect big storehouses inside King's Landing? At least some Kings would care enough about his legacy not to burn the storehouses if civil war threatened; moreover, a King who's knifed in the back by his guardsman doesn't get a chance to burn the storehouse.

Or, maybe folks there just have short memories, short time horizons, or really don't want to think about winter. That's consistent with the diminution of the Night's Watch at Castle Black. But it's not a very satisfying explanation. And, it's not consistent with long time horizons evident in investments in maintaining the honour of the various houses. You can say those are often private goods problems and both the Night Watch and storehouses would be more of a public goods problem given opportunities for predation on storehouses come the winter, but the King's there to solve those kinds of public goods problems. Even if the last King was a drunk and a wastrel, we'd at least see evidence of empty and abandoned storehouses from prior monarchs.

Dixit gave us an excellent analysis of Elaine's optimal sponge-use path in Seinfeld; maybe we can convince him to do this one up more formally too. Or maybe it could be an honours project in a future year. Characterise the optimal crop savings rate given different distributional assumptions on the duration of winter and of the gaps between winters and given different parameters on storage depreciation.

*Update: James Butler finds me the geek resources I needed. But I'm still having problems parsing this.

Seasons and climate

Westeros's climate shifts from arid and dry desert climate in the furthest south to cold and harsh Winters in the north and icy wasteland in the lands of Always Winter in the furthest north.
Westeros and Essos both experience extremely long seasons of varying length, usually lasting at least a couple of years each. The maesters try to predict the length of the seasons, monitoring the temperature and days length, to advise on when to plant and when to harvest and how much food to store. However, given the random nature of the seasons, this is not something that can be relied on.
At the beginning of A Game of Thrones the continent has enjoyed an unusually long decade-long summer of peace and plenty and many fear that an equally long and harsh winter will follow. The winter comes at the outset of A Feast for Crows, with the arrival of the White Ravens from the citadel.
It’s noted that winter means that the days grow shorter. It’s not simply that the weather becomes really cold or really warm, but it was explicitly stated by George R. R. Martin and more than once stated that the explanation of the Planet's climate is magical in nature and will be revealed at the end of the series.

Latest Recorded Seasons
Ok, so do we then have a winter starting at the end of 228 and running through past the false spring of 281? Or starting in 254? Why do we have Winter followed by a 3-year winter? If Maekar's summer led to a short autumn, 228-254 is not autumn. I need a GoT geek.

28 comments:

  1. They're there, but storehouses don't make for exciting settings.

    In the latest book, for example, Castle Black has its storehouses (or more precisely, the inadequacy of said storehouses) discussed in some detail.

    The general state seems to be: some Lords are better prepared than others, and no one knows/cares what the small folk are up to.

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    1. In the Game world, a reasonable chunk of the economy would have to centre around food storage. Why is it the brothelkeeper instead of the Storemaster who's on King's Council?

      Think about the Old Testament parable about the 7 lean years and 7 fat years; Joseph got made chief advisor to the Pharoah and his main job was making sure he got food storage right for the 7 lean years to come. Man, if there's the chance of 60 lean years, how the heck is there no Storemaster prominent in Council?

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    2. I loved that tally of the Night's Watch stores, especially the venison haunches in honey. Gives a cook a great deal to work with... ;)

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  2. I like Game of Thrones but find I have to leave behind any knowledge of economic history when watching it. In particular, the population size seems pretty uncertain. Most of their technology does not need a large population given some sort of glory period in the past for castle building etc., but there does still seem to be a relatively large number of people living off the surplus of others.

    I guess it is supposed to be a fuedal society but I'm not sure it is convincing - we see little little evidence of insitutions etc. The show discusses armies of hundreds of thousands but cities are a jumble of tents. Events have tens of people where you may expect to see more. Part of this is the budget that a TV show has to offer, and the nature of a drama focused on dialogue, but at the very least you'd expect scenes of farmland (and yes, probably storehouses).

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    1. I agreed with you, until Winterfell rallied the banners. That's completely feudal and implies minor lords under the noble houses who each have serfdoms under them.

      The only tent-city was that of the Doth Raki, no?

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  3. Since the probability of exiting from winter depends on the length of the previous summer, season duration is a state variable. Or maybe you use non-time-invariant value functions. Other than that, should be a fairly simple problem.

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    1. That's the starting assumption. But I don't really know if the probability of exiting winter depends on the length of the previous summer. I need a Thrones-nerd to give me the stylized facts.

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    2. I think it's true, but I'm not completely sure. In any case, that would be the only thing which would make the problem interesting. Otherwise it's a straightforward optimal savings problem with income uncertainty:

      V(x)=max{u(c) + beta*E*V(x')} s.t. x'=(1-d)x + y - c, where y is income (random variable) and can take on two values, 0 or y*>0; and E is an expectation operator for the conditional distribution of y' given y (since we'll want persistence in y).

      The problem gets a lot more complicated if we make the transition probabilities dependent on the length of the most recent summer. I can write out that problem as well, but it will take some thinking to figure out how to solve it.

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    3. And that's why writing it out, solving it, and providing appropriate discussion with some comparative statics would make for a fun honours project.

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  4. Underground storage is also a possibility, though this fails to explain the non-presence of a Storemaster on the Council. But underground storage would have advantages is terms of maintaining a constant temperature. They would also be less prone to destruction during war time. Such large underground stores would be big investments, but the society has had several centuries at a relatively constant level of technology, so it's not, I'd have thought, beyond the realms of possibility.

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    1. You'd expect above-ground drying houses for fruit, salting-houses for meats and fish. And graineries are better above-ground as aeration reduces spoilage and dampness encourages germination.

      Think about the position the Egyptians gave to their storemasters where yields fluctuated with flooding and drought. Then magnify that importance by the scale of the problem in Thrones.

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    2. Once dry most stuff could be moved underground though. This would mean that you would expect only a number of above-ground drying and salting houses sufficient for ongoing drying operations. This might not immediately obvious to a casual observer (TV viewer). Whereas, if all storage was above-ground, you would expect that a very high proportion of all buildings would be storage related.

      Good point on granaries, though. This from the Game of Thrones wiki:
      Westeros and Essos both experience seasons of varying length, usually lasting at least a couple of years each. The length of the seasons is completely unpredictable and varies randomly. The maesters of the Citadel keep a close eye on the length of the days in order to try to predict how long the current season will last, but this is an inexact science at best.

      At the time the series opens, the world has been experiencing a summer that has lasted for nine years, which is unusually long, and the maesters fear that an equally long winter will follow. Westeros extends much further north than Essos, so is much more adversely affected by long winters, whilst Essos, which extends into equatorial regions, is typically warmer.

      In the North, the winters are extremely cruel. Lords set aside non-perishable food items for storage against the next winter, whilst many of the North's most notable strongholds are built in favorable areas, such as Winterfell on hot springs or the Dreadfort of House Bolton on volcanic vents. Some castles, like Winterfell, have elaborate greenhouses which permit the growing of vegetables even in the harshest winters. Despite these precautions, famine and starvation is common during Northern winters, and is one of the reasons the North has a small population despite its vast size.

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    3. I also agree with the need for underground storage. It's less of an issue in the North, where it will presumably just get unbearably cold. But down in King's Landing, based on a variety of foods made and mentioned, we can deduce that they may have had an ice house. There is a a neat example of this, albeit later period, at Monticello: http://www.monticello.org/site/house-and-gardens/ice-house.

      Even the Dornish have the ability to serve iced beverages and sherbet, which indicates they, too, may have an ice house. A costly affair, to bring ice down from the far north by ship!

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    4. Problem for the North and elsewhere is that they need to gather and preserve food when ice is hard to get against the time when ice is easy to get...

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  5. In Season 1, it had been about sixty years since the last winter.

    From AWOIAF:
    At the beginning of A Game of Thrones the continent has enjoyed an unusually long decade-long summer of peace and plenty and many fear that an equally long and harsh winter will follow.

    Perhaps you were thinking of something like Helliconia.

    One thing that always gets me is that Westeros is not only at a stage of development roughly equal to that of medieval Europe, but from various references to history (mostly in the books) appears to have been like that for thousands of years. Perhaps the extreme seasons act as a brake on the development of the culture.

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    1. One thing that always gets me is that Westeros is not only at a stage of development roughly equal to that of medieval Europe, but from various references to history (mostly in the books) appears to have been like that for thousands of years. Perhaps the extreme seasons act as a brake on the development of the culture.

      I keep wondering about this when watching it. Warfare tends to be a major driver of technological innovation and if the entire continent was peaceful for centuries under the previous dynasty then that might explain it.

      Note though that Japan maintained a pretty constant level of technology from the end of the warring states period through to the end of the Edo period (250 odd years), and then not a lot of change in three centuries leading up to the warring states period. Also, the fundamentals of Chinese technology didn't change much over the course of a millenia or more.

      Perhaps a magical worldview (common, presumably, in fantasy universes) exerts a strong negative influence on technological innovation.

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    2. Oh boy, you've found me the source of stylized facts. Many thanks, and many thanks for the correction.

      I'm having trouble parsing their recent seasons though.

      Latest Recorded Seasons
      209AL - Spring (The Great Spring Sickness), following the plague came a two year drought.
      211AL - Summer
      221-228 AL - Maekar's summer, broke suddenly and led to a short autumn and a terrible long winter.[1]
      254AL - Winter
      273AL - Three year winter.
      281AL - the Year of the False Spring.
      288-298 AL - the long summer.
      301AL - Winter start.

      Does that mean there was winter 254AL through 288AL? When did winter start after Maekar's summer?

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    3. Yeah I noticed that too. It's a fan resource - exhaustiveness trumps coherence.

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    4. @nzclassicalliberal I'd at least expect strong tech pressure on food preservation. It would be hard for greenhouses to beat stored grain.

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    5. Although, historically, a number of cultures have lasted centuries without significant technological development despite periodic food pressure. The Egypt example you raised earlier being one such. So, over the course of centuries, the inhabitants of Westeros could have become profficient at dealing with regular one or two year winters without that necessarily propelling them beyond a medieval level of technology.

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    6. @nzclassicalliberal: (minor book spoilers): the negative influence you mention is sort of suggested by something that's said in Dance

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  6. Goddammit Eric. You making it very hard to avoid reading the books. I don't want to start because the author is slow. It took 6 years between book 4 and 5 and there are still, at least, another two to go.

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  7. Re: the season timeline and your trouble figuring it out: it's simply a list of seasons that have been mentioned in the books, and hence is not exhaustive. So someone has mentioned that there was a winter in 254, and someone has mentioned that there was a three-year winter in 273. Presumably there was a summer (several, in all likelihood) in between. None have ever been mentioned in the text, however, and so they are not added to the timeline.

    Compare with, "the United States suffered a depression that began in the late 1920s, and a recession in the late 2000s," which does not imply that the United States was in a continuous state of depression for 80 years, after which it entered a recession.

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    1. That makes sense. I'm sure I remember the nursemaid telling of a winter that lasted 60 years though...

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  8. A fun discussion, all around.

    I have to agree that storehouses don't make for good television, especially with tens of characters to work with and develop. But, that said, it's something I've wondered about a great deal in the books.

    One thing that shouldn't be discounted is the ability to buy goods from other regions. I've always been under the (perhaps mistaken) impression that if winter falls at the same time on Essos, that it is at least much less severe. The Night's Watch borrows money in order to buy food in an attempt to keep them fed through the winter, and I imagine that other large holdfasts could do the same.

    However, that touches on another point above, which is that it would be enormously profitable to hoard food stores, then sell them at extortionist rates in winter. Seems like just the sort of thing Littlefinger would do. :) As for him, I think that as long as he keeps the money rolling in, no one especially cares where he finds it.

    Given my particular attention to food in this series, I would love to learn more about historical food preservation. I know that apple recipes, for example, changed throughout the year along with the quality of one's remaining apples.

    This definitely merits further research, and perhaps a scholarly blog post of our own... ;)

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    1. I think bottling here came about the time of Pasteur. But we haven't had the extreme seasonality they have; I'd expect Westeros to be pouring more resources into food preservation tech than we did.

      I had also thought there wasn't much trade, or at least that Castle Black was restricted to locally available goods; perhaps that's just because they've few resources to provide in trade as payment.

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  9. There is one line in the TV series about having stores for a 5 year winter.
    In addition, if it freezes over in the winter, wouldn't that make all of outside a giant freezer?

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    1. Sure, but you have to grow the food before the winter, right?

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