Talk:Lorenz curve
| WikiProject Statistics | |||||||||||||||||
|
|||||||||||||||||
| WikiProject Economics | (Rated Start-class, Low-importance) | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|||||||||||||||||
I agree, I had trouble learning about the Lorenz curve from this page because the cdf is different. The cdf plots the cumulative % of the variable against the category. The Lorenz plots the cumulative % of the variable against the cumulative % of population (calculated from the categories). The first sentence and the graph labeling should be revised. —Preceding unsigned comment added by Intlthahc (talk • contribs) 20:37, 12 January 2008 (UTC)
Is it really a "cumulative" dist. fn. ?? The the y-axis gives the sum as a PERCENTAGE of the total, whereas in the cdf, the y-axis will give the un-normalized sum. This will produce a logrithmic-shaped graph rather than an exponential one... Nigel, May 7, 2006
Contents |
[edit] Convex function?
- is a convex function.
If the variable being measured can take negative values but has a positive mean, then the Lorenz curve will sink below the line of perfect inequality and is a convex function.
If the variable being measured can take negative values and has a negative mean, then the Lorenz curve will be above the line of perfect equality, except at the end points, and is a concave function.
^ I've edited this out. This convex statement is BS. It can easily be non convex and still be monotonic increasing. The graph pictured is misleading. Jasmine85 (talk) 10:07, 3 September 2009 (UTC)
The Lorenz curve is convexe and not concave as is said in the text, see the graph below.
Can we get a real life example for the illustration from some place? Paranoid 20:10, 6 Jan 2005 (UTC)
The Lorenz Curve is used in geography as well to represent unequal distribution of the world's population over area...please add that in
'... we call this line the line of perfect equality or the 45° line.' It's only 45° when both axes have equal scales. Holy Cow 20:55, 18 March 2006 (UTC)
[edit] Discrete Probability Functions
What does a Lorenz curve look like for a discrete probability function? What are the formulas for calculating the curve in such a case? DCary 04:19, 26 May 2006 (UTC)
[edit] x(F)=F-1(f(x))?
Is x(F), the inverse of F(x), equal F-1(f(x))? --Kwj2772 (talk) 13:21, 17 July 2009 (UTC)
[edit] Income or wealth?
The article waffles back and forth on whether this curve typically represents income or wealth, which are completely distinct measures. Which one is kind of important. --75.94.164.123 (talk) 14:11, 28 June 2011 (UTC)
[edit] convex and increasing
would like an explanation (it may have been buried in the math, didn't look) as to why the curve cannot hump above the perfect equality line when non-negative variables are used. It would seem that a decreasing increase is possible. — Preceding unsigned comment added by Barnsward (talk • contribs) 19:42, 15 August 2011 (UTC) never mind, i see that if all are lined up in ascending order on the x axis there has to be an increasing increase. — Preceding unsigned comment added by 69.123.186.12 (talk) 23:17, 15 August 2011 (UTC)
