st: how to test significance for difference

["Isabella King" <isabella.c.king@gmail.com>]

Dear all,

I use -tabulate- to check the distribution of two variables. But I am
interested in the difference. Which code is used to directly give the
difference in value and test the significance? For example, group 1: number
of new firms in area A; group 2: number of new firms in area B. I get the
result and knows the difference. But I do not know whether the difference is
statistically significant. How to test this significance and report the
t-value? 

Another question: When I run regression for two groups, I get two
coefficients, I know the difference, but how to test the significance for
this difference and report the t-value for this difference value?

Any suggestion is appreciated.

Best,
Isabella

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