The same questions about surpluses were asked multiple times, so I know the idea was not crossing. (I fully admit not being a gifted public speaker.

But you seem, from this, to be observant and a quick learner.

Good Luck !!

that makes sense...

I have made simpler schemes..or rather laid them out for others to do. For young teens, for ex. The way to do that, I thought, was to make the energy invested simply ‘work’, ‘effort’, ‘time spent’, which is an intuitive notion - some things are tough, take a lot of physical energy, take time, etc. in contrast to other things that are ‘easy’ appealing to everyday experience, such as (in my case) skimming down a hill on skis, vs. walking up the snowy hill. The stuff harvested (it could be diamonds, or tomatoes, or wheat) are just somehow ‘there’ or appear, ‘grow’ automatically, it is left in the shade. That is a materialist, physicalist approach that skips the ‘economy.’ The metaphor is then something like apples in a orchard (in a closed system), which require ever increasing physical /technological effort to keep the apples coming out to market, and those who harvest them alive.

Eve eating a Big Mac Instead? Heh ;)

Yes, that extra bag for the farmer can be related to WestTexas's Export Land Model.

The farmer and his family, and his livestock must be fed FIRST, before he takes any grain to market. Assume each human needs 9000 seeds a year to feed themselves. Each seed invested will yield ten at harvest ( EROEI=10 ).

The first farmer has poor soil, he eats 9000 seeds a year, and eventually has to sell his farm to pay back his debt.

He harvested nothing. He loses

The second farmer works all by himself.

Problem is he is so inefficient by himself he can only plant one thousand seeds, getting back ten thousand seeds. He eats nine thousand seeds just to survive and power his body. He saves the last thousand seeds for next year.

He slowly loses his farm to the tax man. Overhead kills him.

The third farmer has his family. All together, they can plant six thousand seeds because his wife offloaded all the cooking and washing chores, and left him and his three kids to concentrate on planting and harvest.

They reap sixty thousand seeds. They end up eating 45 thousand seeds. and they save six thousand seeds for next year. This leaves 9000 seeds. Enough to feed the tax man.

The fourth farmer has a family and horse. He nearly doubles his productivity because of the horse. He plants ten thousand seeds, and harvests one hundred thousand seeds.

His family eats 45,000 seeds, the horse eats 20,000 seeds, 10,000 seeds are saved for next year, leaving 25,000 seeds for market. He's feeding his family, his horse, his preacher, and the tax man.

The fifth farmer has a tractor. He plants 100,000 seeds, reaps a million.

His family eats 45,000 seeds. Another 45,000 seeds are sold to buy diesel for the tractor. 100,000 seeds are saved for next year. 10,000 seeds go for tax. 800,000 seeds are available to feed the townspeople. The farm feed itself and almost 90 townfolk.

Now, a problem comes. Fuel for the tractor is getting expensive. Instead of exchanging 45,000 seeds for fuel, its 100,000 seeds. Six less people get fed.

Then its 200,000 seeds for fuel, and sometimes can't get fuel at all. Half the crop is lost because its harvest time and the tractor won't run without fuel. His EROEI has dropped to 5.

His family still eats 45,000 seeds. 100,000 are still saved to plant next year, the farmer is still out 200,000 seeds sold for the diesel fuel he did get. Taxes still got 10,000 seeds. Out of his meager harvest of 500,000 seeds, 145,000 seeds are left. Enough for sixteen people - but 90 townfolk were counting on him. Seventy four people will not get fed.

Having seventy four heads around without something to put in their tummies is not a pretty sight. There is apt to be much physical argument concerning which tummy gets the remaining food. If they destroy the farmer's infrastructure in the melee, even more tummies will not get fed.

Anyway, thats my take on this whole thing.