Thanks I think its important to understand that this effect seems to apply anytime you hit a critical resource constraint. If its wages or labor for example you get a traditional wage price spiral. This classic spiral works for example to limit investment in production expansion as wages increases and prices increase to compensate. Eventually assuming that resources remain constant the system collapses in some manner.

Recessions for various reasons can be seen as when one of a myriad of critical economic conditions change such that they are relatively negative. Negative EROEI is simply a case where the system is permanently negative and classical economic changes cannot alter the condition. Bottom line once the system is fundamentally negative in a critical resource no economic game on earth can change the situation its physically constrained. This does not mean that the dwindling remaining wealth cannot flow in various directions but the overall system is in contraction and in general it will do its best to minimize the contraction rate. Attempts to alter this simply cause collapse to occur somewhere in the system.

Thus its 100% certain that if the oil industry actually tried to expand significantly under the conditions of negative EROEI regardless of the price of oil it will simply cause the economy to collapse elsewhere to pay for the expansion. The direct link may be difficult to ascertain because the real link is via a shared financial network and thus shared economic structure. Exactly how the system modifies itself is not clear this is simply because the repeated conversions of real wealth into money and debt serve to cloud and transfer the effects throughout the economy.

However since this is fundamental you can ignore money its simply not relevant.

Consider the case of the chicken farmer and the feed seller. The exchange is pure barter x chickens for x amount of feed.

Lets say at first the chicken farm can trade 5 chickens for enough feed for 10.
He then grows ten and trades for enough feed for 15 and so on.

Eventually lets say the feed provides actually produces less feed.
Then the table turns the first trade lets say the feed seller demands 25 chickens for feed for 20.

Next trade he has less feed so he demands 15 chickens for enough feed for 10.

Its obvious how the balance works and its obvious that although the feed seller made more chickens for less feed the overall system declines.

The feed seller could demanded as many chickens as he wished if we add in the ability of the chicken farmer to borrow chickens in trade then you can play the game a bit longer. But it should be obvious it does not matter. Bottom line if you have less feed you have less chickens its a fundamental physical fact and its impossible to game the trade to change the situation in any meaningful way. People that only take the view point of the feed seller or the chicken seller completely miss the overall situation I assert your forced to look at the overall balance to correctly determine the economic condition if one of the critical resources is in decline any other viewpoint is simply ignoring the real problem.

Finally as and addition you can see that if the feed farmer needs 20 chickens to produce feed for 15 it simply ain't gonna happen thats what people claim will happen when prices increase. Sure the feed seller can do what ever he wishes he could require 50 chickens in exchange for feed for one and then produce feed for 20 but demand 100 chickens all possible ways to game the system simply are that games.

To be clear by negative EROEI I mean negative vs the needs of the society. This happens well before EROEI drops to 1:1 or less I'd suggest it depends on the complexity of the society at what level it enters a situation that it can no longer sustain itself.

Simpler societies can probably get away with very low EROEI's since simplicity simply means most members of society are themselves involved in energy/food procurement. Then net gain or complexity level is trivial to determine its the amount of food/energy they produce in excess of what they can consume. More complex societies both make the required net gain larger and make it more difficult to calculate the minimum. I've tried using the concept of the typical support pyramid for a core industry to calculate the minimum EROEI. The idea is that you take a key industry say for example farmers and determine how many people are needed to directly support the modern farmer. The simple calculation of how many people are involved in actually planting and harvesting that leads to and assertion that 1-2% of the population are farmers is simply bullshit. It does not include the gene engineers at monsanto or the fertilzer or tractor manufactures nor does it include the prepared food industry needed to process the centralized food stores etc etc etc. My best guess is at least 30% of the population is indirectly involved in the food industry from frozen foods to actual farming. We changed the nature of the work but I'd argue it has not really fallen from its low of 40% just the work has changed from direct planting. On top of this you have additional support industries such as housing for those in the food industry and cars and doctors etc every modern person uses a very generic set of services regardless of what the core industry is that creates the initial wealth. I make a WAG that this adds 10-20% to the total bring the number of people that make a living off of food up close to 50% of the population.

So if everyone else supported the energy and other commodity industries like metals you need at least a 2:1 EROEI to break even. Of course outside of food the rest of the various core industries have their own support pyramids just guess that they are 10% each.
This leads to a ballpark figure of 10:1 for the minimum energy industry direct EROEI before the society structure as a whole is negative. You can cut down my estimate for food but I worked pretty hard at it and was surprised how much of the worlds economy is directly then indirectly related to supplying food. And I don't think its wrong. And even if I'm off its easy to imagine that other industries can certainly command a bigger part of the economic pie then I've allocated bottom line is you can come up with about 10:1 or 15:1 repeatedly using various estimates of our support pyramid for our modern economies.

If right and your paper is right and we have dropped into the 3-5:1 range then one would expect that the economy would fall into a collapse rivaling the Great Depression in magnitude.

Ohh wait ..