How do you define the principal-agent problem when appied to govt, though? Govt and its departments are not 'owned', and cabinet secretaries and even Presidents are not principals. Who is the 'principal': that particular govt's most powerful donors and lobbyists? Also, govt has both career and political appointees, the latter can change every 4/8 years. So seems to me there are multiple groups of agents/parties.

So when you say 'does not benefit any defensible purpose of government', is that a statement about political science, rather than two-party govt system with lots of lobbying? I mean it seems like any policy you could concoct would benefit some (posibly small) interest-group of people somewhere, unless it was 100% wasteful.

[0]: https://www.investopedia.com/ask/answers/041315/how-principl...