Serving the Quantitative Finance Community

 
User avatar
dramao
Topic Author
Posts: 0
Joined: March 25th, 2015, 1:20 am

Textbook problem - Comparing Risk Aversion

March 26th, 2015, 1:36 am

I got stuck on this textbook problem.. On x>0, one von Neumann-Morgenstern utility function is given by x1-R, with 0<R<1, and another is given by x1-R + x1-Q, with 0<R<1 and 0<Q<1. In the sense of Arrow and Pratt, which is more risk averse and over what domain? Using the concept of strong risk aversion, is either more risk averse than the other for all x>0?Any idea how to solve it?I calculated the risk aversion for the utility functions respectively, but I can't compare the results.
 
User avatar
kermittfrog
Posts: 23
Joined: September 9th, 2010, 10:25 am
Location: Frankfurt

Textbook problem - Comparing Risk Aversion

April 29th, 2015, 7:46 am

Say A is the "only r" guy,B is the "r and q" guy, then - if I remember ocrrectly - A is more risk averse than B around x iff ARA_A(x) > ARA_B(x), where ARA is absolute level of risk aversion around x.Knowing that absolute risk aversion ARA(x) computes to -u''(x)/u'(x), we can write down both ARA:ARA_A>ARA_B-u_A''/u_A'>-u_B''/u_B'u_B'/u_A'>u_B''/u_A''...1>q/ri.e., B is more RA than A, iff q>r. Hope that helps.
 
User avatar
ExSan
Posts: 493
Joined: April 12th, 2003, 10:40 am

Textbook problem - Comparing Risk Aversion

April 29th, 2015, 10:31 am

QuoteOriginally posted by: dramaoI got stuck on this textbook problem.. On x>0, one von Neumann-Morgenstern utility function is given by x1-R, with 0<R<1, and another is given by x1-R + x1-Q, with 0<R<1 and 0<Q<1. In the sense of Arrow and Pratt, which is more risk averse and over what domain? Using the concept of strong risk aversion, is either more risk averse than the other for all x>0?Any idea how to solve it?I calculated the risk aversion for the utility functions respectively, but I can't compare the results.which text book?
°°° About ExSan bit.ly/3U5bIdq °°°