Economist Ed Glaeser has an interesting essay up here.
I say interesting because he takes an unusual approach to libertarianism. Rather than arguing that small government is more efficient, he tailors the message to liberals by emphasizing egalitarianism.
In this situation, we can view libertarianism as an ideological innovation that Ed Glaeser is trying to market.
According to Everett Rogers in The Diffusion of Innovations, one of the main determinants of the diffusion of an innovation is its compatibility with other products or knowledge. Because of cognitive conservatism (resistance to changing one's mind-- the best explanation I can find online is here), it can be difficult to get people to adopt new opinions.
By proposing that libertarianism is compatible with egalitarianism, Glaeser is trying to minimize the cognitive resistance from liberals. Instead of asking them to abandon their views on egalitarianism, which would require a major ideological overhaul, he asks them to alter their views on the best strategy-- still requiring an ideological overhaul, but only a modest one.
Looking at this from an economic perspective, Glaeser is trying to lower the ideological costs of libertarianism for liberals.