We look at the annual Census Bureau\'s Current Population Survey data to analyze predictors of higher income.

1. Cheannette Smith
Jeffrey Moise
Amanda Rollason

3.  www.census.gov
 1994 Current Population Survey
 16 ≤ AGE ≤ 100, HRS>0, & FNLWGT>1

4.  48,842 observations
 1 binary target: INCOME
 6 numeric variables:
AGE, FNLWGT, , , HOURS, EDUC
 9 character variables:
WORKCLASS, EDUCATION, MARITAL,
OCCUPTION, LIVING, RACE, GENDER,
COUNTRY, CHRS

5.  REPLACEMENT node
 INCOME
▪ <50K = ‘0’
▪ >50K & >50K. = ‘1’
 MARITAL
▪ Married-spouse-absent
▪ Married-civ-spouse
▪ Married-AF-spouse
 FILTER node
 FNLWGT

9. Variable Importance
NAME NRULES NSURROGATES IMPORTANCE
Age 12 1 1.00000
Hours 11 4 0.90826
Marital 0 6 0.74237
Occupation 0 6 0.71019
Educ 0 9 0.70266
Race 0 1 0.07123
Gender 0 1 0.07101

11. PUREST LEAF
IF EDUC < 12.5
AND GAIN < 7073.5
AND LIVING IS ONE OF:
Single, W/ Parents,
Other, or Other
Relative
THEN

12. EXAMPLE – RECORD 44
GENDER=Male, AGE=57,
EDUC=13 (Bachelors),
HOURS=40, MARITAL=Married,
OCCUPATION=Prof./Spec. and
INCOME=>$50K
IF HOURS > 31 AND AGE
> 28.5 AND OCCUPATION
IS ONE OF: Prof/Spec,
Sales, Exec/Man, Tech
Support, or Pr. Serv.
AND EDUC > 12.5
AND MARITAL = Married
THEN

13. 3 branches & 31 leaves

14.  Stepwise Selection Method
 6 steps showed 5 statistically significant variables

15.  Record 44 (again)
 GENDER=Male, AGE=57, EDUC=13 (Bachelors), FNLWGT=337895,
HOURS=40, MARITAL=Married, WORKCLASS = Federal Gov’t, and
OCCUPATION = Professional/Specialty
 INCOME=>$50K
 Y44 = -10.1113 + 0.0302(57) + 0.4009(13) + 8.14E-7(337895)
+ 0.0543(40) – 0.3885(0) – 0.1892(0) + 1.9460(1)
– 0.3355(0) – 0.6681(0)
= 1.2148
 The probability that he would make greater than $50,000 is
e1.2148 / (1 + e1.2148) = 0.7712.
 This is more than 50%, so he is likely to make greater than $50,000

17.  Get hitched.
 Stay in school.
= MORE MONEY*
 Grow old.
 Work Hard.
*83% of the time

18.  More Detail in Income
 Interval vs. Binary
 Types of Wages
 Use more recent Census data
 Compare Trends Over Time
 Updated for Today’s Demographics and
Labor Industries

19.  Originally Extracted by Ronni Kohavi
and Barry Becker from the PUMS
database
 1994 was the first year of a major
overhaul in the CPS definitions of
employment and industry
 CPS data determines the quarterly
unemployment rates

20. Thank you.