Ramarao Kanneganti (also Lambert Strether) link to an article on water problems and farm subsidies in the west of USA Holy Crop: How federal dollars are financing the water crisis in the west. Lambert Strether's reaction:
"Interesting read on “Killing the Colorado”:

Growing cotton in the desert, long term, may be doomed.

Ya think? But it seems to me that the entire venture of setting up huge cities in the desert may have issues of its own. And to my taste, the theme of the Pro Publica article is a bit too close to “market distortions caused by evil government” for my taste, as if somehow Big Gummint forced people to live in the habitat they in fact systematically optimized for their own lifestyle and profit. Maybe water should be managed as a common pool resource, and not private property at all?"

Ramarao's reaction "The problem is that the current policies are holdover from the great depression era. Once we create an entitlement program, it is tough to take it away. Just like how the government did not pull the plug on Detroit car industry in the 70's that prolonged the misery (if it put in the money to do the transition, it would have been better). The current agricultural policies in the US often do not make sense."

These subsidies also figure in the Bali Bali package which India fought hard to dilute. Finally, it seems to a program that outlived its useful and in the current conditions seems to be detrimental to all.

P.S. A long report from the Congress of the US Congressional Budget Office notes the relation of aid to trade.