I am persuaded that the concepts of fragility and robustness of political-economic-social systems are more productive than the concept of efficiency. Markets are amazingly robust as evidenced by their self-correcting capacity. Socialism, on the other hand, is extremely fragile and any deviation from ideal conditions leads quickly to acute problems. Pete Leeson and I discuss the relative robustness and fragility of liberalism and socialism in our paper in Journal of Markets & Morality.
However, market societies are fragile in their own way. One of Hayek's most challenging propositions is that our evolutionary past has 'hard-wired' us for norms appropriate for small group settings, while modernity and the extended order of the 'Great Society' requires us to adopt norms and morality appropriate for anonymous interactions. In sorting out the implications of these tensions between the intimate order of our tribal past and the extended order of social cooperation under the division of labor it is vital to get an accurate picture of Hayek's theory of cultural evolution and spontaneous order. I published a paper in the journal Cultural Dynamics in 1990 attempting to do that.
The bottom line is that while we don't need to understand in order to experience that benefits of a spontaneous order, we may very much need to understand deeply the principle of spontaneous order in order to sustain the extended order of the 'Great Society'. Thus, the number #1 role of the economist in society, as James Buchanan often told us in his classes, was to teach citizens the principle of spontaneous order. See, e.g., Buchanan's essay "Economics as Public Science," in Foundations of Research in Economics edited by Steve Medema and Warren Samuels.
Anyway, a very challenging paper on the fragility of modernity that can be found in Gerard Radnitzky's essay "Science as a Particular Mode of Thinking and the Taming of the State".
Thanks for Rafe Champion for the pointer.