A mathematical approach to economics Are there books or papers where economics is formalized and studied very rigorously? I am very interested in this topic. I would preferably like free online books and/or papers, but that is not necessary.
 A: Be careful of what you wish for... Bernt Stigun's book "Towards a Formal Science of Economics: The Axiomatic Method in Economics" probably goes above and beyond of what you had in mind when asking for rigor. He starts with mathematical logic (first-order languages)...
http://www.amazon.com/Toward-Formal-Science-Economics-Econometrics/dp/0262192845/
Also I have a vague impression some research in "epistemic game theory" may use the axiomatic approach but I might be wrong.
A: Gerard Debreu's Theory of Value provides a mathematically rigorous analysis of the theory of general equilibrium in economics. It is considered a classic by many economists and won the author a Nobel Prize in Economics. 
Here's the link to the pdf of the monograph: http://cowles.econ.yale.edu/P/cm/m17/m17-all.pdf. 
A: You might be interested in Economics for mathematicians by Cassels. It is more focused on what mathematicians find interesting, rather than what economists find useful. 
A: Axiomatic Theory of Economics, 1999, by Victor Aguilar
This is a short 26-page simplified exposition written at the undergraduate level:
http://axiomaticeconomics.com/Axiomatic_Economics_Article_by_Aguilar.pdf
A: You can check the Handbook of mathematical economics edited by Michael Intriligator, Kenneth Arrow.
In general, the Handbooks in Economics contains several interesting topics.
Handbooks page
