Assorted links by Tyler Cowen April 5, 2014 at 12:45 pm in 1. What is the marginal rate of substitution between dogs and sloths? 2. A robot doctor for space travel? 3. Why higher education will have to change (by the way GMU does quite well by this ROI metric). And universities and retirement communities: are those the real economies of scope? 4. The anternet. 5. Are the makers of 3-D printers getting a reality check?