Igor Pak’s “Lectures on Discrete and Polyhedral Geometry”

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Here is a link to Igor Pak’s  book on Discrete and Polyhedral Geometry  (free download) . And here is just the table of contents.

It is a wonderful book, full of gems, contains original look on many important directions, things that cannot be found elsewhere, and great beyond great pictures (which really help to understand the mathematics). Grab it!

 

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Praise For ‘Gina says’

Praise for: ” ‘Gina Says,’ Adventures in the Blogsphere String War

(Below the dividing line:  Greg Kuperberg, Scott Aaronson, Clifford Johnson, Peter Woit, Motty Perry, Caterina Calsamiglia, Yuval Peres, Eva Illouz, and (right from the comment section)  Luca Trevisan, Thomas Love, John Sidles, Jacques Distler, Marni D Sheppeard, (and from other journals/blogs) Hamish Johnston, Lance Fortnow. New: Lubos Motl, Eytan Sheshinski and Tselil Schramm.

Download the first part of the book (pdf file) (See also this post)

   Shmuel Weinberger (August 07): Very much enjoyed the story of Gina’s involvement in the blog world– i read it through on my flight back to America. It was a very interesting if occasionally difficult read. Probably the part that resonated most was the advice (i think it came from your father) that every subject is fascinating after you study it deeply.

Avi Wigderson: (August 07)  I expected no less from the author of the immortal translation of the classic book “Where is Pluto?

Oded Schramm (Dec 2007): Though it is somewhat uneven, there were some definite enjoyable highlights. (Feb. 08 ) What about a sequel? I’m really curious what’s happening with Gina these days?

ראה תמונה בגודל מלא

Itai Benjamini It was such a joy to listen to your unique voice (music) yet again. A typo: Section 20 “children’s teaching disabilities” should be “children learning disabilities”. (Feb 08 ):

 

Elchanan Mossel (Feb 08): I read it when I was sick and couldn’t do other things, and it cheered me up

 

 

ראה תמונה בגודל מלאOlle Haggstrom (March 08): I found it a real page-turner, and read the entire thing for four straight hours last night! Very interesting stuff, on several levels. And very original, of course. May I ask what is your relation to Gina? You seem to have remarkable insight into her mind…

 

Ken Binmore (June 08) Dear Gil, I like your book a lot. If you get it published, it could do with Continue reading

What do Firms Want?

Here is another little sectionette from my book review  “Economics and Common Sense” on Steven Landsburg’s book “More sex is Safe Sex: The Unconventional Wisdom of Economics”, that just appeared on the AMS Notices site. Of course this topic can lead to a lovely discussion. Update (March 2011): Here is a related discussion on Noam Nisan’s blog in the context of research grants offered by Google.

What do firms want? Reading Landsburg’s book, one gets the impression that firms and their owners and executives just want to maximize their profits. They will avoid polluting the environment if and only if this is good for business. They will obey the law if and only if the cost/benefit tradeoff in violating the law are unfavorable.

It is not clear if this characterization of what firms want is just an assumption essential for developing the theory (which is reasonable), or an approximation of reality (which also sounds reasonable), or perhaps a solid precise description of reality (which as such sounds unreasonable), or maybe a normative teaching of economics theory (which sounds unfortunate), or perhaps even a representation of moral values (which also sounds unreasonable).

This description is simplistic even in the context of classical economic theory, Continue reading

Is More Sex Safe? A book review.

I was asked by the Notices of the AMS to review the book “More Sex is Safe Sex: The Unconventional Wisdom  of Econmics” by Steven E. Landsburg.  My review entitled “Economics and Common Sense”, will appeared in the June/July issue of the Notices and you can find it here. (And in the August issue of the AMS Notices, there is will be a book review by Olle Häggström on John Allen Paulos’ new book: “Irreligion”.)

In his book, Steven E. Landsburg uses the “weapons of evidence and logic, especially the logic of economics” to draw surprising insights which run against common sense. “If common sense tells you otherwise,” says Landsburg, “remember that common sense also tells you that the Earth is flat”.     

I will include a few little sectionettes from the review here in this post. Some of the issues raised in this book are related to many discussions and debates we had over the years at the Center for the Study of Rationality of the Hebrew University of Jerusalem. Questions regarding “efficiency,” “subsedies,” “monopolies,” “labor union,” “differential salaries,” “law and economics,” “rationality and the judicial system,” and various other related topics were amply discussed at the Center, and some of these topics and discussions are related to issues raised in Landsburg’s book.

 

The Unconventional Wisdom of Economics

 

  

The Armchair Economist 

Sometime after writing my review, I saw in the Yale book store, along with several copies of Landsburg’s new book, a copy of his older book from the early 90s, “The Armchair Economist”. I bought it and read some of the chapters. So before quoting excerpts from my book review on the new book let me first talk a little bit about the older book. Several chapters are devoted to describing some classic teachings of economics, such as general equilibrium theory, and they are very good. I liked Landsburg’s explanation of the notion of “efficiency” – it is the best popular explanation of “efficiency” I read or listened to.

The Peltzman Effect

Armchair Economist starts with an interesting finding from the 1970s by Sam Peltzman, a U. of Chicago economist, asserting that safety seat belts have led to an increase in the number of car accidents, and that the net effect on death from car-accidents, which is reduced by the direct effect of seat belts and other safety measures, but which at the same time is increased by the indirect effect of drivers taking more risks because of these safety measures, is close to zero. Peltzman’s study also asserts that seat belts have raised pedestrian death toll caused by accidents.

Continue reading