USA, University of Minnesota, www.ipums.org,
Steven Ruggles, Sarah Flood, Ronald Goeken, Josiah Grover, Erin Meyer, Jose Pacas and
Matthew Sobek. IPUMS USA: Version 7.0 [dataset]. Minneapolis, MN: IPUMS, 2020.
https://doi.org/10.18128/D010.V10.0
The PUMA-to-county restriction was done using MABLE,
http://mcdc.missouri.edu/websas/geocorr12.html
This problem set uses a subsample of demographic data for Denver.
The sample was drawn according to the values in the variable "perwt". This is a weight
value provided by the US Census Bureau to correct for differences between the sampled
population and the target population. It is called a sample weight or an expansion weight.
It can be thought of as the number of people in Colorado that the one observation
represents in terms of demographic characteristics. For example, if you add all the weights
in the original sample for all of Colorado, you will get an approximation of the population of
Colorado in the sample year. If you multiply the "age" variable by "perwt" then divide by
the sum of the "perwt" values, you will get an approximation of the average age in the state,
whether or not the ages of the cases are present in the same proportion in the sample as in
the population./nThe category "educ"=7 corresponds to 1 year of college. The category "educ"=10
corresponds to 4 years of college.
Samples of size 40 are drawn from the responses with "educ"=7 and with "educ"=10
according to the weights in the data set and saved in "dat_7_10.RData".
IPUMS Data
Read in the subsample of the IPUMS data.
load("dat_7_10. RData")
2.a
(10 points)
Please run and interpret a Mann-Whitney U test comparing "incwage" for the observations
with "educ" equal to 7 and with "educ" equal to 10. In your interpretation, please consider
the case in which you treat the distributions of the two populations as related by
translation and the case in which you don't make this assumption.
ggplot (dat.7.10, aes (x-incwage, color-factor (educ)))+geom_density()/ndensity
1.5e-05-
1.0e-05-
5.0e-06-
0.0e+00-
Oe+00 1e+05 2e+05 3e+05 4e+05 5e+05
incwage
factor(educ)
7
10
2.b
(10 points)
Please run a Mann-Whitney U test comparing log(incwage) for the observations with
"educ" equal to 7 and with "educ" equal to 10 and compare to the result in part a. Please
explain what you observe about the two tests.
Fig: 1
Fig: 2
Fig: 3