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name: <unnamed>
log: C:\Documents and Settings\Michael Rosenfeld\My Documents\newer web pages\soc_meth_proj3\fall_2011_381_logs\class one.log
log type: text
opened on: 27 Sep 2011, 12:29:15
. *class starts here
. memory
bytes
--------------------------------------------------------------------
Details of set memory usage
overhead (pointers) 534,840 1.02%
data 14,574,390 27.80%
----------------------------
data + overhead 15,109,230 28.82%
free 37,319,562 71.18%
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Total allocated 52,428,792 100.00%
--------------------------------------------------------------------
Other memory usage
set maxvar usage 2,001,730
set matsize usage 1,315,200
programs, saved results, etc. 77,387
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Total 3,394,317
-------------------------------------------------------
Grand total 55,823,109
. describe
Contains data from C:\Documents and Settings\Michael Rosenfeld\Desktop\cps_mar_2
> 000_new_unchanged.dta
obs: 133,710
vars: 55 1 Feb 2009 13:36
size: 15,109,230 (71.2% of memory free)
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storage display value
variable name type format label variable label
--------------------------------------------------------------------------------
year int %8.0g yearlbl Survey year
serial long %12.0g seriallbl
Household serial number
hhwt float %9.0g hhwtlbl Household weight
region byte %27.0g regionlbl
Region and division
statefip byte %57.0g statefiplbl
State (FIPS code)
metro byte %27.0g metrolbl Metropolitan central city status
metarea int %50.0g metarealbl
Metropolitan area
ownershp byte %21.0g ownershplbl
Ownership of dwelling
hhincome long %12.0g hhincomelbl
Total household income
pubhous byte %8.0g pubhouslbl
Living in public housing
foodstmp byte %8.0g foodstmplbl
Food stamp recipiency
pernum byte %8.0g pernumlbl
Person number in sample unit
perwt float %9.0g perwtlbl Person weight
momloc byte %8.0g momloclbl
Mother's location in the household
poploc byte %8.0g poploclbl
Father's location in the household
sploc byte %8.0g sploclbl Spouse's location in household
famsize byte %25.0g famsizelbl
Number of own family members in hh
nchild byte %18.0g nchildlbl
Number of own children in
household
nchlt5 byte %23.0g nchlt5lbl
Number of own children under age 5
in hh
nsibs byte %18.0g nsibslbl Number of own siblings in
household
relate int %34.0g relatelbl
Relationship to household head
age byte %19.0g agelbl Age
sex byte %8.0g sexlbl Sex
race int %37.0g racelbl Race
marst byte %23.0g marstlbl Marital status
popstat byte %14.0g popstatlbl
Adult civilian, armed forces, or
child
bpl long %27.0g bpllbl Birthplace
yrimmig int %11.0g yrimmiglbl
Year of immigration
citizen byte %31.0g citizenlbl
Citizenship status
mbpl long %27.0g mbpllbl Mother's birthplace
fbpl long %27.0g fbpllbl Father's birthplace
hispan int %29.0g hispanlbl
Hispanic origin
educ99 byte %38.0g educ99lbl
Educational attainment, 1990
educrec byte %23.0g educreclbl
Educational attainment recode
schlcoll byte %45.0g schlcolllbl
School or college attendance
empstat byte %30.0g empstatlbl
Employment status
occ1990 int %78.0g occ1990lbl
Occupation, 1990 basis
wkswork1 byte %8.0g wkswork1lbl
Weeks worked last year
hrswork byte %8.0g hrsworklbl
Hours worked last week
uhrswork byte %13.0g uhrsworklbl
Usual hours worked per week (last
yr)
hourwage int %8.0g hourwagelbl
Hourly wage
union byte %33.0g unionlbl Union membership
inctot long %12.0g Total personal income
incwage long %12.0g Wage and salary income
incss long %12.0g Social Security income
incwelfr long %12.0g Welfare (public assistance) income
vetstat byte %10.0g vetstatlbl
Veteran status
vetlast byte %26.0g vetlastlbl
Veteran's most recent period of
service
disabwrk byte %34.0g disabwrklbl
Work disability
health byte %9.0g healthlbl
Health status
inclugh byte %8.0g inclughlbl
Included in employer group health
plan last year
himcaid byte %8.0g himcaidlbl
Covered by Medicaid last year
ftotval double %10.0g ftotvallbl
Total family income
perwt_rounded float %9.0g integer perwt, negative values
recoded to 0
yrsed float %9.0g based on educrec
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Sorted by: sex
. tabulate race
Race | Freq. Percent Cum.
--------------------------------------+-----------------------------------
White | 113,475 84.87 84.87
Black/Negro | 13,626 10.19 95.06
American Indian/Aleut/Eskimo | 1,894 1.42 96.47
Asian or Pacific Islander | 4,715 3.53 100.00
--------------------------------------+-----------------------------------
Total | 133,710 100.00
. tabulate race [fweight= perwt_rounded]
Race | Freq. Percent Cum.
--------------------------------------+-----------------------------------
White |224,806,952 82.02 82.02
Black/Negro | 35,508,668 12.96 94.98
American Indian/Aleut/Eskimo | 2,847,473 1.04 96.01
Asian or Pacific Islander | 10,924,728 3.99 100.00
--------------------------------------+-----------------------------------
Total |274,087,821 100.00
* there are 133K individuals in the dataset, which represent a sampling frame of 274 million non-institutional US persons in March, 2000.
. summarize perwt_rounded
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
perwt_roun~d | 133710 2049.868 1083.244 93 14281
* Average weight is 2049, because the CPS is a roughly 1-in-2000 sample of the US.
. tabulate race, nolab
Race | Freq. Percent Cum.
------------+-----------------------------------
100 | 113,475 84.87 84.87
200 | 13,626 10.19 95.06
300 | 1,894 1.42 96.47
650 | 4,715 3.53 100.00
------------+-----------------------------------
Total | 133,710 100.00
* Note that even the categorical variables like race are coded as numbers, the value names "white" etc are just labels attached to the variable value codes.
. summarize incwage
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
incwage | 103226 19462.59 28843.38 0 364302
. summarize incwage if age> 29 & age<50
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
incwage | 40613 28463.12 31838.35 0 362302
. summarize incwage if age> 29 & age<50 & incwage>0
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
incwage | 33069 34956.38 31905.33 1 362302
* we use the if, the "&" which means "and" and we also use the "|" to indicate "or" to select subsamples of interest, here people age 30-49 with positive income in 1999.
. sort sex
. by sex: summarize yrsed
--------------------------------------------------------------------------------
-> sex = Male
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
yrsed | 49353 12.79632 3.217925 0 17
--------------------------------------------------------------------------------
-> sex = Female
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
yrsed | 53873 12.75218 3.098084 0 17
* It seems like men have a tiny bit more education than women on average, but…
. by sex: summarize yrsed if age >= 25 & age<=34
--------------------------------------------------------------------------------
-> sex = Male
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
yrsed | 9027 13.31212 2.967666 0 17
--------------------------------------------------------------------------------
-> sex = Female
Variable | Obs Mean Std. Dev. Min Max
-------------+--------------------------------------------------------
yrsed | 9511 13.55657 2.854472 0 17
* Among younger folks, women have a little more. Within the CPS sample, we are 100% sure that the women in this age category have higher mean education, because there are no unknowns. The real question is whether this small difference between men and women's average education in the CPS implies that women age 25-34 in the whole US have higher educational attainment than men of the same age. That is a question that we will use statistics to answer. The answer is, almost certainly yes:
. ttest yrsed if age>=25 & age<=34, by(sex)
Two-sample t test with equal variances
------------------------------------------------------------------------------
Group | Obs Mean Std. Err. Std. Dev. [95% Conf. Interval]
---------+--------------------------------------------------------------------
Male | 9027 13.31212 .0312351 2.967666 13.25089 13.37335
Female | 9511 13.55657 .0292693 2.854472 13.49919 13.61394
---------+--------------------------------------------------------------------
combined | 18538 13.43753 .0213921 2.912627 13.3956 13.47946
---------+--------------------------------------------------------------------
diff | -.2444469 .0427623 -.3282649 -.1606289
------------------------------------------------------------------------------
diff = mean(Male) - mean(Female) t = -5.7164
Ho: diff = 0 degrees of freedom = 18536
Ha: diff < 0 Ha: diff != 0 Ha: diff > 0
Pr(T < t) = 0.0000 Pr(|T| > |t|) = 0.0000 Pr(T > t) = 1.0000
. log close
name: <unnamed>
log: C:\Documents and Settings\Michael Rosenfeld\My Documents\newer web
> pages\soc_meth_proj3\fall_2011_381_logs\class one.log
log type: text
closed on: 27 Sep 2011, 15:08:18
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