Bryan Caplan advocates pacifism.
He lives in Fairfax County, which has one of the more militarized and non-pacifistic police forces in the United States. Fairfax SWAT teams murder dentists who wager on sports; best I'm aware, Sal Culosi's murderer is still on the police force. Here is the list of people officially killed under authority of the State of Virginia since 1982. I'm not going to make a guess as to the Caplan household tax burden, but about a fifth of his federal taxes go to the military.
How much weight does pacifism have in Bryan's overall utility function? He almost certainly rightly concludes that the total amount of pacifism in the world is unaffected by his marginal tax contribution to Virginian and American anti-pacifism, and that he probably does more to further pacifism where he is now as compared to moving to a place like New Zealand where less than a twentieth of his taxes would go to pay for a military whose main function is assisting in civil defence, emergencies, and enforcing property rights in fishing quotas in New Zealand's territorial waters.* But if Bryan's pacifism includes an unwillingness to pay for a war machine as well as a refusal to serve in one, I'd be very happy to have Bryan as a neighbour some day.
* Here's the appropriation summary for Vote.Defence 2010. Total NZ military spending of some $2.85 billion includes only some $79 million on "operational deployments"; I'd have to guess most of that is the Afghanistan deployment. If I'm one of two million or so taxpayers, my share is about $40. I doubt that the overall Afghanistan mission passes cost benefit, but at least the NZ involvement is relatively minor. New Zealand has no air combat wing (Kiwis are flightless). This has far less to do with New Zealanders being inherently pacifistic than with that we face such tiny external threat, and such low odds of repelling any country with sufficient blue water forces to actually get out here, that the optimal level of national defence is near zero.