2
votes
1answer
77 views

Using control variables in Difference in Difference method

When random experiments are conducted, 'baseline data' are usually used as control variables in order to increase precision. How about control variables in Difference in Difference method? What I ...
0
votes
1answer
38 views

Common or regional time dummies as controls: Does it make a difference?

I am analyzing policy diffusion using panel data, and the inclusion of temporal controls substantially influences my results. I'm wondering if it can theoretically make a difference for the estimates ...
3
votes
1answer
163 views

How to explain control variables and interaction effects

I'm a bit stuck on running a GLM between 3 continuous variables in R. I can't make them categorical as it removes the significance. I have two questions. I'm analysing data on eggs. I had read that ...
1
vote
0answers
23 views

Controlling for respondents' propensity to rate high/low or moderate/extreme

I am doing a simple linear regression to test the relationship between voters' self-reported policy stands and their approval ratings for two hypothetical presidential candidates in a simulated ...
4
votes
2answers
65 views

How can I calculate the effect of my equipment on my sport's performance?

I'm doing a stationary sport like golf, so the details matter. I'm recording each of my scores with detailed information about the equipment I'm using, and the weather conditions. So 1 score has 2-3 ...
1
vote
0answers
47 views

Unexpected correlation, Method to account for the shared variance

Summary: While looking at the correlations I noticed a wired, relation. Variables: User comments - A; User community activity- B; Comments on user's wall - C (control) I expected that A and B will ...
2
votes
1answer
144 views

How to control for a variable

The goal of the analysis is to find a correlation between birth context and stature, while controlling for age. Each person has an ID number, age, stature, and birth context. That last part is what ...
0
votes
0answers
87 views

Too many controls?

I am purposely keeping this question vague since this has happened to me with multiple datasets. I have a DV and a few IV then several controls, and all looks fine. Then I add one more controls and ...
0
votes
1answer
140 views

Partial correlation

I want to create a regression model to predict state crime rate. There are two variables among 10 ( Vi= # of violent crimes per 100,000 population, Vi2 = # of violent crimes per 10,000 population) ...
5
votes
3answers
1k views

How to control for market return in an (SPSS) OLS?

Please consider the following panel dataset: ...