The real rationale is simple vote-seeking - politicians aim for votes, not the state's well-being, and the two can diverge. Only a small percentage of the population actually works in agriculture in the West (about 5% in the European Union in 1997 and 1.7% in the United States in 1990). The subsidies that benefit this minority indirectly drive up food prices for the majority (that milk carton you buy actually cost more to make than you paid for it - the other 40% of its cost came from your tax dollars which the government gave to the farmer who made it!). Why, then, would this state of affairs persist in a democracy? Since the harm to the >95% is relatively minor, it is not usually enough to change their voting pattern; whereas it is almost the sole issue for the <5%. Thus, it arguably makes political sense to maintain subsidies.