Generate a mean that varies over time

[Lola Nait]

Hello!
I have data from a Survey since 1976.
What I am trying to do is get to see how education for different race groups evolved over Time
Educ is a continuous variable
So I try to generate mean education and see how this evolved over time for different race group.
However when I do the following code I get the attached file

egen meaneduc=mean(educ)

. graph twoway line mean educ, by(race)

. graph twoway line meaneduc year, by(race)


Meaning, it calculated the average mean over the given period of time, but what I want to see is how the average education level for each year evolved by race ? how can I do it???

[Nick Cox]

It's hard to follow what you did.

Look at your syntax and your results.

Your mean variable

egen meaneduc=mean(educ)

contains only the mean over all observations. That's a constant.

Asking for separate graphs by race and year should not produce a variation on showing the same constant again and again.

[Marcos Almeida]

You could perform a regression analysis, then get the margins and marginsplot.

[Lola Nait]

It's hard to follow what you did.

Look at your syntax and your results.

Your mean variable

egen meaneduc=mean(educ)

contains only the mean over all observations. That's a constant.

Asking for separate graphs by race and year should not produce a variation on showing the same constant again and again.

Sorry im new to STATA, how do I see the evolution of the mean over time for different race?

[Lola Nait]

You could perform a regression analysis, then get the margins and marginsplot.

But if I do
reg wage white
for e.g.
this would only give me how average wage for white compares to average white for non white
But how do I see the evolution over time ?
because if I do
reg wage white year
then year is simply the year in numerical number so effectively it gives me the impact of an additional year in wages but how do I move from that to the evolution of wage across year for white people?

[Nick Cox]

Being new to Stata is precisely why you should read and act on the FAQ Advice and present a consistent question. No data example here, but my guess is that you should try

egen wanted = mean(educ), by(race year)
line wanted year, by(race) sort