which is better

Chebyshev or Herffingdahl? And why? These two always confuse me. At least I know bootstrapping to a T.

Chebyshev is really easy. On the test they might ask you what percent of a distribution lies within k standard deviations of the mean. If they use the word Normal in there, gotta use the normal tables. If they don’t, the answer is “at least 1 - 1/k^2”. Herfindahl (check spelling above) would just ask you some question like A controls 70% of the market while 3 other firms control 10%. Calc the HI. Ans: 0.7^2 + 0.1^2 * 3 These should be easy points (like easier than bootstrapping)

if questions like this come up, i’ll be happy… if you know the formula its an easy mark