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No, because - as we went over at considerable length in the thread above - a t-test with Gaussian uncertainties requires that the uncertainties are uniform, which they manifestly are not.

If you must insist on treating these three points as independent - which I can see little justification for doing, but maybe that's just me - you do a (casualties, indictments, convictions) plot and run a linear fit against all three points in a given series at the same time. This way you get some more meaningful (implicit) assumptions about the way the uncertainties look.

- Jake

If you only spend 20 minutes of the rest of your life on economics, go spend them here.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Tue Mar 17th, 2009 at 07:54:52 AM EST
[ Parent ]
The sensible thing to do is a fit in a log-log plot - the "intercept" is the quantity of interest here, and the "slope" is being taken as 1 but could be fitted too.

Or, rather, three fits.

One for all six rows in Vladimir's table - that's the "null hypothesis".

One for the 3 Serb rows and the 3 non-serb rows. That's more or less equivalent to was was done in the diary.

Or you could do a test on whether the 3 Serb and 3 non-Serb points fall above or below the "null hypothesis" regression line. The trouble is, with only 6 points you probably can't say anything with 95% confidence.

Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith

by Migeru (migeru at eurotrib dot com) on Tue Mar 17th, 2009 at 08:06:03 AM EST
[ Parent ]
AFAICT, that's substantially the same thing I'm doing below.

I would be opposed to fitting the slope as well as the intercept in your model, because we already only have three points for every fit parameter - and you fit a number of parameters comparable to your number of data points at the peril of talking nonsense...

- Jake

If you only spend 20 minutes of the rest of your life on economics, go spend them here.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Tue Mar 17th, 2009 at 09:05:43 AM EST
[ Parent ]
This is what happens when you set the slope to 1 and only fit the intercept:

This actually makes it look worse for Vladimir's hypothesis.
The fit is this:

Coefficients:
(Intercept)  
     -6.095  

Response: log(indicted) - log(casualties)
	  Df  Sum Sq Mean Sq F value Pr(>F)
Residuals  5 1.24772 0.24954  


Most economists teach a theoretical framework that has been shown to be fundamentally useless. -- James K. Galbraith
by Migeru (migeru at eurotrib dot com) on Wed Mar 18th, 2009 at 03:01:38 AM EST
[ Parent ]

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