Hello,

I'm using the Blinder-Oaxaca decomposition to study the wage differentials between males and females. I used logarithm or hourly wages to do that and reported the pooled method. I read a lot of research papers including Jann's paper and I feel like I understand 100% what the decomposition equations mean. However, I'm a little confused if 1) my results make sense; 2) how to make interpretations for these coefficients and 3) will I need to pick a reference category (because I thought we are always comparing same category between males and females so for example, looking at the married variable, I'm comparing married females to married males.. so won't married males be automatically considered the reference here for me.. same for educational attainment, when reporting a female with a bachelor degree, isn't a male with a bachelor degree considered automatically to be the reference group). Looking at one of my results below, I would make these conclusions but I'm not sure if that's the right way to do it... am I using percentage points versus percent correctly?

1- The total gender pay gap in 2001, calculated with hourly wages was 28 percentage points.

2- Differences in the characteristics of males and females explains less than half of the total gap. (E.g. 0.0775254/0.2759044 = 28 percent)

3- Age is estimated to explain 0.15808 percentage points of the total wage gap of 0.2759044 or 57.6% of the total gap. However, the effect of age tapper over time (looking at age square having a negative sign

4- Having a high school degree (a female with a high school compared to a male with high school) is also contributing to an increase in the gender wage gap by 0.0002263 percentage points (or 0.0002263/0.2759044 = 0.08 percent)

5- Completing a bachelor’s degree (a female with a bachelor degree compared to a male with bachelor degree) will reduce the gender wage gap by 4 percent (-0.113391/0.2759044)

6- can do the same with single females/single males, and married females/married males? right

7- Looking at working full time (FTW), is this coefficients comparing females working full time versus males working full time? or females working full time versus females working part time (which I think would be wrong)?. how would this be interpreted?




Blinder-Oaxaca decomposition Number of obs = 30,330
Model = linear
Group 1: female = 0 N of obs 1 = 15540
Group 2: female = 1 N of obs 2 = 14790

------------------------------------------------------------------------------
| Robust
lnHwages | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------------
overall |
group_1 | 10.28898 .0040482 2541.60 0.000 10.28105 10.29692
group_2 | 10.01308 .0041629 2405.33 0.000 10.00492 10.02124
difference | .2759044 .0058067 47.51 0.000 .2645235 .2872853
explained | .0775254 .0030875 25.11 0.000 .0714741 .0835767
unexplained | .198379 .0054102 36.67 0.000 .1877752 .2089828
-------------+----------------------------------------------------------------
explained |
hschool | .0002263 .0001441 1.57 0.116 -.000056 .0005087
Bachdegree | -.0113391 .0009713 -11.67 0.000 -.0132429 -.0094353
Married | .0078862 .0011745 6.71 0.000 .0055842 .0101881
Single | -.0018602 .0005965 -3.12 0.002 -.0030293 -.0006911
kid | -.0003125 .0001162 -2.69 0.007 -.0005403 -.0000848
age | .15808 .0074566 21.20 0.000 .1434652 .1726947
age2 | -.145693 .0064581 -22.56 0.000 -.1583506 -.1330354
FTW | .0652989 .0015793 41.35 0.000 .0622035 .0683942
-------------+----------------------------------------------------------------
unexplained |
hschool | .0234703 .0026166 8.97 0.000 .0183419 .0285987
Bachdegree | .0008703 .0014974 0.58 0.561 -.0020646 .0038053
Married | .0462083 .0435611 1.06 0.289 -.0391699 .1315866
Single | .0074362 .0052602 1.41 0.157 -.0028736 .017746
kid | .0080418 .007342 1.10 0.273 -.0063482 .0224318
age | .4657228 .1505767 3.09 0.002 .1705979 .7608478
age2 | -.0623104 .0809454 -0.77 0.441 -.2209605 .0963397
FTW | .1212236 .016439 7.37 0.000 .0890037 .1534436
_cons | -.3995266 .0858276 -4.65 0.000 -.5677457 -.2313076

------------------------------------------------------------------------------

Any help will be greatly appreciated

Thank you