[thrown_22]

That's a gross oversimplification of the premodern economic system. You could only grow food crops next to navigable rivers, they doubled in price for every 20 miles they were transported overland. This meant that the majority of land could only be used for subsistence farming because nothing else could keep the people working the land from starving. Cash crops like frankincense were the only ones that could be grown without easy boat access because they were worth more than their weight in gold.

[lifeisstillgood]

Well 20 miles from a navigable river looks a lot like most of populated Europe and China...

But I absolutely take the point - anything that can fit in an online comment is a gross simplification- especially for "farming since invention of agriculture".

Also the 20 mile is not a hard limit - it's easy to envisage some kind of system where I grow my cash crops near transport like river or coast, and sell them on a trade network, and you grow different crops further out and bring them not to the river / coast but to me to feed me. That probably will be more efficient but just look at the network of trust and possible disasters required - only very stable politics would allow anything like that - and that stability was rare. China probably had more of that for more of the past 2000 years than anywhere else - and that may be the cause of the invention of the bureaucrat!

[thrown_22]

Navigable for a barge and navigable for a canoe are two very different things.

The Danube and the Rhine were the two major rivers that could be navigated by Romans and they were the borders of the empire for that reason: they were the only way to supply border garrisons efficiently. They also had the Nile which isn't _in_ Egypt, but _is_ Egypt.

China by comparison is three major rivers which change course frequently and violently: https://www.youtube.com/watch?v=QFsQoY32n5g

[Someone]

> The Danube and the Rhine were the two major rivers that could be navigated by Romans and they were the borders of the empire for that reason: they were the only way to supply border garrisons efficiently

I don’t see why the southern shore of the river would be easier to keep supplied from those rivers than the northern one. So, if the empire ended there because of supply issues, wouldn’t it end a short distance north of the river?

Also, wouldn’t those rivers only help supply from other border areas, not from the much larger inner parts of the empire?

I would think those rivers just are natural boundaries because they provide some protection against invading enemies.

[thrown_22]

>I don’t see why the southern shore of the river would be easier to keep supplied from those rivers than the northern one. So, if the empire ended there because of supply issues, wouldn’t it end a short distance north of the river?

Retreat is easier when not drowning.

[zasdffaa]

The "doubled in price for every 20 miles" bit is extremely interesting, do you have anything I can follow this up on, thanks.

[denton-scratch]

https://acoup.blog/2019/07/12/collections-the-lonely-city-pa...

Brett says that moving grain by road would double the cost for every 100 miles. He has quite a few articles on premodern farming, and may have given a different figure in other articles.

[hinkley]

> by road

Roman roads were high tech for the era and those were still pretty bumpy. A modern road is much more efficient. Bouncing over uneven terrain not only damages the products and veg it also causes wear and tear on the cart, the animals, and the driver.

Also doubling isn’t a bad thing for the first couple of multiples. Each doubling increases the supply by a factor of four on open terrain. It’s no accident that big cities are at the confluence of trade routes. Up in the mountains creates a funnel that raises the average cost and lowers the reliability of everything too much. It’s like you’ve blockaded yourself.

[denton-scratch]

Travelling by horse and cart can't be much faster than 30 miles per day. So even if you're only 30 miles away, you have a day to get there, a day at the market, and a day to get back. That's 3 days you're not working on the farm. You and the horse that pulls the cart, which of course also needs feeding, and whose day-job is ploughing.

[turtleyacht]

These kinds of insights for old-school roleplaying (OSR) games. Hard to farm out of books, but very insightful having stumbled upon it. And it's not just needing to be true in an absolute, historical sense, but a useful mechanic to save for later.

[thrown_22]

If you want a good overview of a bunch of similar ideas: https://www.youtube.com/watch?v=AvZlXaGEzwg&list=PLsOFk2nGmz...

A course that goes over how everything we think is bad today is good in a world stuck in the Malthusian trap. Working harder today to have a better life tomorrow just means your children working harder tomorrow to have the same life you have today.

The option he didn't talk about at all was how in such a world sexism could keep average living standards quite high so long as all women of reproductive age were kept in near starvation so they could barely carry children to term. But there's only so much unthinkableness you can expect from someone living in the current day lecturing at a university.

[turtleyacht]

Thank-you. I see it is part of Professor Gregory Clark's A Farewell to Alms: A Brief Economic History of the World. And that is part of a series of 49 books, The Princeton Economic History of the Western World.

Definitely sounds like a reference gold mine.

[lifeisstillgood]

My (limited) understanding of the book is that basically during the 19C in Britain, poor uneducated (and unproductive) people died off leaving space for the middle class to grow. Which leads to the conclusion that killing the ooor leads to economic growth. As a thesis it may be short of ... something.

I may have misunderstood the tweet of the review of the article based on the book.

Anyway, my general conclusion is that however hard it is to understand history, understanding economic history is twice as opaque

[thrown_22]

Rather the opposite actually. During the 19th century for reasons that have nothing to do with demography the British learned how to use the poor who would have died to do productive work instead. Then for reasons that have everything to do with child mortality people stopped having 7 children per woman _before_ contraception became widely available. This is the reason why France is smaller than Germany today. Their child mortality decreased faster than Germany's.

[lifeisstillgood]

Yeah your approach is the more usual commonly accepted idea - poor people stopped dying moved to cities got educated became a productive middle class.

The above quoted book tried to argue that the poor dying continued and the middle classes of victorian briton had more kids and hence took over - a sort of poorly argued eugenics wrapped in the usual "it's culture innit" argument.

However Like I say I have only read enough of the book to decide it's in my reading list only after I discover immortality.