I had some of the students in my finance class actually do some empirical work on capital structures, to see if we could find any obvious patterns in the data, but we couldn't see any.

Macroeconomics: A Neoclassical Introduction. ; R. Miller (1991).

He shared the Nobel Memorial Prize in Economic Sciences in 1990 along with Harry Markowitz and William Sharpe. Miller spent most of his academic career at the University of Chicago's Booth School of Business.