The WTO's World Trade Report 2010 is full of interesting trade tidbits. To the extent I have time, I'll pull some out over the next few months. This is from Chapter E of the report:
in the absence of domestic consumption, a domestic production quota is equivalent to an export quota. Yet, while an export quota is prohibited by Article XI of the GATT, most observers consider that a production quota is not subject to this prohibition. Instead, many consider that decisions concerning how much of a natural resource is extracted or harvested fall within the sovereignty of each state
This statement is true to some extent, but I'm not sure it gives a full picture of the issue. One of the reasons for an export quota is to give domestic consumers greater access to the product. With a greater supply on the domestic market, the price should come down for these consumers. Such a policy can be used to give domestic producers who use the good in question as an input -- who are one type of consumer -- an advantage over their foreign competitors. The domestic producers get it cheaper (due to greater supply); the foreign producers pay more (due to reduced supply).
By contrast, I don't think this can be the case with the production quota situation described above. It is true that if there is a production quota, and no domestic consumption, a limit on production will mean a limit on exports. So if production is 100 units, and all 100 are exported, a production quota set at 50 will bring exports down to 50. However, the assumption is that there is no domestic consumption, and I don't see any reason to think that the production quota would lead to any. As a result, it's not clear to me how this production quota could be used to help domestic producers in relation to their competitors, in the way that an export quota would.
So, yes, this kind of production quota is equivalent to an export quota in some sense. But I don't think it can be used in quite the same way as a trade policy tool.
Now, it may be true that a production quota could be used simply to hurt foreign consumers of the product, even where there is no domestic consumption. I don't know if this is ever the case in practice, but it is possible. But it also may be that the government is concerned about overusing scarce resources, and the production quota is designed to address that problem.
