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       log:  /Users/baum/Desktop/771bs1.smcl
  log type:  smcl
 opened on:  18 Jan 2004, 13:01:37



. set more off



. set seed 123456789



. local reps 1000



. 
. webuse census2, clear
(1980 Census data by state)



. summ age



    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
         age |        50        29.5    1.752549         24         35



. ci age



    Variable |        Obs        Mean    Std. Err.       [95% Conf. Interval]
-------------+---------------------------------------------------------------
         age |         50        29.5    .2478479        29.00193    29.99807



. bootstrap "summ age" r(mean) r(sd), reps(`reps') saving(771bs1) replace



command:      summ age
statistics:   _bs_1      = r(mean)
              _bs_2      = r(sd)



Warning:  Since summ is not an estimation command or does not set e(sample),
          bootstrap has no way to determine which observations are used in
          calculating the statistics and so assumes that all observations are
          used.  This means no observations will be excluded from the
          resampling due to missing values or other reasons.



          If the assumption is not true, press Break, save the data, and drop
          the observations that are to be excluded.  Be sure the dataset in
          memory contains only the relevant data.






Bootstrap statistics                              Number of obs    =        50
                                                  Replications     =      1000



------------------------------------------------------------------------------
Variable     |  Reps  Observed      Bias  Std. Err. [95% Conf. Interval]
-------------+----------------------------------------------------------------
       _bs_1 |  1000      29.5    .00334  .2374498   29.03404   29.96596   (N)
             |                                          29.04      29.99   (P)
             |                                          29.06         30  (BC)
       _bs_2 |  1000  1.752549 -.0224573  .2554975   1.251176   2.253923   (N)
             |                                       1.228065   2.217784   (P)
             |                                       1.277913   2.260937  (BC)
------------------------------------------------------------------------------
Note:  N   = normal
       P   = percentile
       BC  = bias-corrected



. 
. use 771bs1,clear
(bootstrap: summ age)



. graph drop _all



. histogram _bs_1, normal name(g771bs1_m) 
(bin=29, start=28.780001, width=.04896552)



. histogram _bs_2, normal name(g771bs1_s)
(bin=29, start=1.0879676, width=.05032897)



. graph combine g771bs1_m g771bs1_s, col(1) ///
>    ti("Bootstrap distributions of mean and standard error")



. graph save 771bs.pdf, replace
(file 771bs.pdf saved)



. 
. log close
       log:  /Users/baum/Desktop/771bs1.smcl
  log type:  smcl
 closed on:  18 Jan 2004, 13:01:52
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