One-tail or two-tail one, manager, control

pawn

Hi,

VAR mean-variance approach, one tail or two tail?


Quality control chart? H0: manager adds no value, blar blar blar.... one tail or two tail?

bkballa

Var - one tail - used to measure downside risk

Quality control - one tail - company making statistical checks on the quality of its medical products is only interested in whether their product has fallen significantly below an acceptable standard.

dyga

idreesz Wrote:
-------------------------------------------------------
> Var - one tail - used to measure downside risk
>
> Quality control - one tail - company making
> statistical checks on the quality of its medical
> products is only interested in whether their
> product has fallen significantly below an
> acceptable standard.

Hi

Don't you think the quality control chart looks two-tail?


thx

Roflnadal

Var - one tail

QC chart: two tail since the null hypothesis is that the manager does not add any value: expected return - benchmark return= 0, so there is an upperbound and a lowerbound for the confidence band which narrows over the years.