Linklist: April 30, 2012

New Scientist: One Per Cent: Expressive car sends its ’emotions’ ahead

Tyler Cowan notes: Amy Finkelstein wins the John Bates Clark award. Transportationistas may remember her mention here for her work on E-Z Tax

Wikipedia: Rocket mail

Arnold Kling: My Thoughts on Technology and :

“I think that urbanization increases the demand for government. When people are crowded together, many more externalities are created. Water and sewage management become a huge deal. So does planning a road and transportation system.
Technology for long-distance trade also increases the demand for standardization and enforcement of standards. That is likely to raise the demand for government.”

Jason Scheppers writes in at Kids Prefer Cheese: We Get Letters: Polls on I-95. The general point is that if a road is uncongested, and tolls are imposed which reduce use, this is a welfare loss. This is why we should continue to use average rather than marginal cost payment systems for uncongested roads (which is most of them), like the flat mileage-based user fee (in the future), gas tax or worse, property taxes. We still need to pay for the road if it is a worthwhile part of the network, but differential tolls or tolls on some uncongested roads but not others are not terribly efficient (though it may be profitable for the toll collector). The beauty of the gas tax (over the property tax) is that it better gets at road users in proportion to use.