What is a quasi concave utility function?
What is a quasi concave utility function?
In mathematics, a quasiconvex function is a real-valued function defined on an interval or on a convex subset of a real vector space such that the inverse image of any set of the form. is a convex set. For a function of a single variable, along any stretch of the curve the highest point is one of the endpoints.
How do you know if a utility function is quasi concave?
if f(x) ≥ f(x’) then f((1−λ)x + λx’) > f(x’). That is, a function is strictly quasiconcave if every point, except the endpoints, on any line segment joining points on two level curves yields a higher value for the function than does any point on the level curve corresponding to the lower value of the function.
Is quasiconcave a utility function?
A utility function is quasi–concave if and only if the preferences represented by that utility function are convex. A utility function is strictly quasi–concave if and only if the preferences represented by that utility function are strictly convex.
What is the difference between convex and concave function?
A function of a single variable is concave if every line segment joining two points on its graph does not lie above the graph at any point. Symmetrically, a function of a single variable is convex if every line segment joining two points on its graph does not lie below the graph at any point.
What is strictly concave?
A function is called strictly concave if. for any and . For a function , this second definition merely states that for every strictly between and , the point on the graph of is above the straight line joining the points and .
What are different types of utility functions?
What follows is a brief overview of the four types of utility functions you have/will encounter in Economics 203: Cobb-Douglas; perfect complements, perfect substitutes, and quasi-linear.
What is a strictly concave function?
Is ex concave or convex?
Example: The graph of ex is always concave up because the second derivative of ex is ex, which is positive for all real numbers. The roots and thus the inflection points are x=0 and x=35. For any value greater than 35, the value of 0″>f′′(x)>0 and thus the graph is convex.