For the most part, free market think tanks and conservative advocacy groups are allies in the war against big government.
But typically, they part ways when it comes to one issue: consumption taxes.
Think tanks, and for that matter most economists, tend to support consumption taxes as more efficient and more business friendly.
Advocacy groups, on the other hand, see them as nothing but a tax grab.
We see this difference of opinion playing out right now in Ontario, where the Liberal government is in the process of "harmonizing" the PST and the GST.
The think tanky C.D. Howe Institute thinks it's a great idea, whereas the advocacy-oriented Canadian Taxpayers Federation says it's a disaster.
I remember a similar split happening back in 1989 when the Mulroney government was implementing the Goods and Services Tax.
At the time I was working for the National Citizens Coalition and one day we held a meeting to determine our stance.
Somebody at the meeting noted that the Fraser Institute had come out in favour of the GST for all sorts of valid reasons, so perhaps the NCC should too.
At which point, our political consultant snorted: "The NCC can never, ever come out in favour of a tax. Your supporters would revolt!"
So we bashed the GST like crazy -- which upset some economists but made our supporters very happy.