Thinking about the margins in politics

My friend (though we’ve never met) and fellow economist Jon Murphy recently said in a comment on co-blogger Pierre Lemieux’s recent post:

If there are two options that take you off the desired path, it’s not really better to choose the one that takes you away a little more slowly.

I challenged Jon and wrote:

Yes that is true. Think in the margins.

Jon is good at thinking on the margins. I thought he would agree. But he didn’t. Instead he wrote:

I am David. My point is that both options presented take me further from my goal. That implies it’s time to look for a new margin or do nothing.

Commenter Vivian Darkbloom came to my side of the issue and wrote:

Standing on the 30 yard line is not the same as standing on the 10 yard line!

To which Jon responded:

Agreed. But if my goal is to be in the end zone, one play that gets me back to the 40 and the other that gets me back to the 50 are both counterproductive.

Yes, both are counterproductive, but in economics we often compare two bad alternatives and choose the less bad one. Marginal thinking also works here. 40 is closer than 50.

If Jon had argued that the two alternatives were not different, he would have a point. But he made it very clear that that is not what he claims.

Note: Pierre raises another issue in response in the comments, and it’s a good point for Pierre to raise. But it’s not relevant to my response to Jon.