Dear all,

A (probably silly) question about the bootstrap command.
When trying to bootstrap a coefficient, one can save the estimated coefficient for each resampling/bootstrap iteration, and pile them up in a dataset.
When summarizing the aforementioned coefficient , I get an average that is different from the bootstrap results (while the sd are exactly identical.)
Below is an example that hopefully will illustrate/clarify:

Code:
cap program drop Test
program define Test, rclass
    preserve
    reg price mpg weight length
    clear
    return scalar coeff = _b[mpg]/_b[weight]
    end

sysuse auto, clear
bootstrap r(coeff), reps(50) seed(123) saving(bla, replace): Test 
use bla, clear
su _bs_1
Could you please help me understand why the su _bs_1 yields a different value compared to the results returned by the bootstrap ?

Thanks a lot,
Alex.