Development, geography, and economic theory

I got this about a year ago (before his Nobel was awarded) and didn't get around to reading it until recently. I should have really enjoyed it, since it covers several topics I enjoy (history, economics, development of cities). However, there was something about ... I don't know, maybe the tone. Krugman comes off as arrogant or smug or something through the first 2/3 of the book; I couldn't decide if he was being directly critical of people he actually admired, if he was sarcastically praising his opponents with back-handed compliments before dismissing them, or damning them with faint praise. Maybe it's the fact that he seems very, very deeply buried in academia and uses language that assumes that the audience spends most of their days developing and critiquing formal economic models.I don't know if I got used to it, or simply started to catch on to (or perhaps remember?) the jargon, or Krugman began to warm to the topic, or what, but I think I actually turned a corner in the last 1/3 and began enjoying it. It could also be that the book is not about Development and Geography, but about the life and death of theories in modern academia. That is a subject area that would seem to have a very narrow audience indeed.As far as the maths, I guess I would have liked to see a commitment to either deliver a serious lecture and support it with equations and charts and get them right, or to leave that stuff out entirely. There is a chart and some discussion of it in the first section, but the lecture makes such vague references to it that it is not clear whether the chart is wrong or if he was annotating it with notes during the live lecture that did not make it into the book. Similarly, the appendix contains a few equations, but since not all terms are defined, it seems to be nearly useless. Is that really e, the base of the natural logarithm? How in the world did that get into the equation? Maybe arbitrary introduction of variables is just some archaic practice among economists that makes engineers wince? But now I'm being overly critical of a book that is not intended to be a battering ram of an argument, but rather just a romp through the death and life of theories.