The Making of Economic Policy begins by observing that most countries' trade policies are so blatantly contrary to all the prescriptions of the economist that there is no way to understand this discrepancy except by delving into the politics. The same is true for many other dimensions of...

This paper studies invariance relationships in tick-by-tick transaction data in the U.S. stock market. Over the 1993–2001 period, the estimated monthly regression coefficients of the log of trade arrival rate on the log of trading activity have an almost constant value of 0.666, strikingly...