st: t test in stata

[Caroline Wilson <wilson_cj@hotmail.com>]

Hi everyone,

I'm trying to determine whether there is a statistically significant change in two proportions between two years, 2005 and 2010. I understand I can use a t-test for this, provided the sample size is large enough. However, I'm not sure whether I should conduct a paired t-test or an unpaired t-test because there are some of the same subjects in both years, but for the most part the two groups represent different subjects.  In this case, is it better to conduct paired t-test because at least some of the same people are in both years? 

Any advice would be much appreciated!
Carrie 		 	   		   		 	   		  
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