# Concept of Utility in demand systems

I have seen that researchers use different utility function in demand systems estimation such as Stone Geary. What is the role of these utility functions? What are utility function other than stone Geary?

• For examples of standard utility functions used in introductory courses see economics.stackexchange.com/questions/41980/…, that should at least partly answer the second part of your question. May 16 at 16:47
• Utility function encode the preferences of economic agents so market basket $x_1$ is (weakly) preferred to market baske $x_2$ if and only if $U(x_1) \geq U(x_2)$ where $U$ is the utility function. May 16 at 16:49