Actually here's a link on the NIEO that you might find interesting.
http://web.nps.navy.mil/~relooney/routledge_15b.htm
That the current squabbles at the WTO meeting have empahasized the problem of commodities reflects that problem-
(1) that the northern countries can outproduce commodities (where possible) better than the countries of the South.
(2) that countries of the South have been losing in the economic scheme of things to the countries of the North because of lower commodity costs relative to manufactured goods.
There is a good reason for (1). Historically agriculture was considered to be labor intensive. Your basic farmer pushing a plow behind an OX, or the peasant who tends his rice paddy behind a water buffalo, is true only in the South. In the North, farming is capital intensive. Consider the way that livestock is harvested (in large factory like buildings in which the animal never goes outside but is just fattened and then slaughtered. But also consider the cost of a harvester or the chemicals and enhanced seeds that go into crops. YOu can find that in the developed North, but in the South where its painfully difficult to get fertilizer and seeds- forget harvesters- its still a labor business.
This has had some painful effects in the US as well. As capital-intensive agriculture replaces labor intensive, small and medium farmers are being pushed out because they can't compete. In the film "The River" with Sissy Spacek and Mel Gibson, one sees some of that issue back in the 1980s. McDonalds, from what I have been told, gets much of its beef from a few big cattle corporations.
(2) Is partly because of the power of the North but also because of the problems of the South.
When you look at a lot of your weaker countries, your developing countries, in many cases it is commodities that becomes the dominant source of direct or indirect taxation. We see this in the move to nationalize mining companies in the 1970s and 80s, but also in the high prices commodities are charged to export. Simply, these countries rely on those commodities to eat. Because they are so poor, and often inherited administrative structures from colonial authorities, they have no other means of revenue. They can't charge personal income taxes, as much of the developed world does, because they don't have the infrastructure for it. Otherwise they have to borrow or get aid. Since aid has been in decrease, that means borrowing, but most are already in debt from the oil shocks of the 1970s up.
To give you an illustration of how bad the infrastructure is compared to the US. In the US, you get a bill, you write a check, put in in an envelope, slap a stamp on it, and mail. In Brazil you usually have to go to the bank to pay all your bills, and the banks are usually full. The reason why is that in the US we can trust our mail- a public service from the government. In Brazil, you can't. And Brazil is one of the better countries.
Now compare prices. If you were to go to most developing countries with your own dietary needs you would find that you would have to spend more, perhaps twice as much. Despite being agricultural countries- much of the agriculture is cash crops for export, and much of the best food is shipped out. Indeed, most of the people couldn't afford it. Thus malnutrition and lower productivity.
Lower commodity prices leads to lower public revenue for education, law enforcement, or support for capital investment.
Back to Brazil, a cop makes about $300 per month. Cost of living in food would probably be at least that for a family of 4. Plus housing, plus bills, and you can see why most of the cops corrupt and no one trusts them. If you have cops you can't trust or who are crooked, how much faith can you have in a system to protect your property rights? If you can't have secure property rights, you can't have investment. And so it goes.