Interpreting Univariate Difference-in-Difference Results

[Goon Yip Lee]

Hi, I'm doing a difference-in-difference analysis on how the ESG reform in Hong Kong affected firm value. My study period ranges from 2013-2017 with the shock happening in 2016.

I have performed a univariate difference-in-difference but I'm not sure how to interpret the results.
The code I used was: diff tobinq_w if fisc_year>=2014 & fisc_year<=2017, t( treatment_vol) p( crisis)
treatment_vol is a dummy variable that gets a value of 1 if firms have complied with the reform and crisis is a dummy variable that gets a value of 1 if the years are 2016 and 2017
These are my results
DIFFERENCE-IN-DIFFERENCES ESTIMATION RESULTS
Number of observations in the DIFF-IN-DIFF: 6174
Before After
Control: 2846 2906 5752
Treated: 160 262 422
3006 3168
--------------------------------------------------------
Outcome var. | tobin~w | S. Err. | |t| | P>|t|
----------------+---------+---------+---------+---------
Before | | | |
Control | 1.888 | | |
Treated | 1.317 | | |
Diff (T-C) | -0.570 | 0.168 | -3.40 | 0.001***
After | | | |
Control | 1.798 | | |
Treated | 1.515 | | |
Diff (T-C) | -0.283 | 0.133 | 2.12 | 0.034**
| | | |
Diff-in-Diff | 0.288 | 0.215 | 1.34 | 0.180
--------------------------------------------------------
R-square: 0.00
* Means and Standard Errors are estimated by linear regression
**Inference: *** p<0.01; ** p<0.05; * p<0.1
Diff (T-C) is significant for before and after, so does that mean the reform had a positive effect on firm value?

really appreciate any help i can get! Thanks in advance

[Phil Bromiley]

You didn't get a quick answer. You'll increase your chances of a helpful answer by following the FAQ on asking questions.

Your question seems to be extremely basic. Have you read material on univariate d-i-d estimation and models? It looks like the treated are significantly lower than controls before, and less lower after, but the difference in difference is not statistically significant so you cannot reject the hypothesis that treated and controlled changed the same amount.