I found this essay: “Public Choice: Politics Without Romance,” by James M. Buchanan, on the excellent (though pro-imperialism-tending) aldaily.com website.
“Armed with nothing more than the rudimentary insights from public choice, persons could understand why, once established, bureaucracies tend to grow apparently without limit and without connection to initially promised functions. They could understand why pork-barrel politics dominated the attention of legislators; why there seems to be a direct relationship between the overall size of government and the investment in efforts to secure special concessions from government (rent seeking); why the tax system is described by the increasing number of special credits, exemptions, and loopholes; why balanced budgets are so hard to secure; and why strategically placed industries secure tariff protection.”