I have said before that capitalism is predatory system, an extension of our own predatory nature as opportunists. Well lets apply a ecosystem model to the american economic model. Granted, I understand biological principals better than I understand the economy, but this is my blog and since few seem to want to comment to correct me, I am going to take it as silent agreement.
First of all, an ecosystem isn't quite the closed loop everyone was taught in elementary school. There has to be a point source of energy. In the natural world this is the sun. The next level up are the plants that harvest this energy from the sun to create chemical energy that (with very few exceptions like extremaphiles living on deep ocean volcanic vents) all life is ultimately dependent on. After that comes (and I am grossly over simplifying this) are the organisms that feed on mostly or strictly on plant matter. Beyond that are carnivores up to apex predators.
So our base level is one in the same. According to Jared Diamond and his superbly researched "Guns, Germs, and Steel", human civilization didn't begin to develop until after the domestication of staple crops. Once we were able to generate a surplus of food and do it on the same land year in and year out, we were able to transition from hunter/gather groups into more complex social stratification. Ultimately, everything you own from the computer you are using to view this to the clothes you are wearing while reading this (and if you are not wearing clothes, er... well... this just got awkward) is all a result of the first human who figured out that planting seeds leads to regular harvests of food.
So farmers are our plankton if you will. Next up are the filter feeders, the shrimps and tiny organisms that live on what the plankton harvest from the sun. Now here is where it gets tricky, sunlight isn't all that is necessary for the subsection of the system to function. Money must flow back to the farmers (fertilizer, water, nutrients if you will) so they can use them to grow more crops. What good is having a half million brussel sprouts if you cannot exchange them for the goods and services you need. The next tier up and (this is important) all subsequent tiers after provide this to the farmer.
The role of the filter feeders is to transport and transmute the energy collected from the farmers to higher tiers. Laborers eat and work. Shrimp eat and get eaten. Money from labor earnings go back to the farmer. Effluent and decomposing bodies provide nutrients to plankton.
next time "the role of middlemen and how the bank bailouts probably will end up hurting the banks much more than it ever helped".