I estimate an ordinal logistic regression model and use 'oparallel' to get the p-value from a Brant test:

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ologit rep77 foreign

oparallel, brant

This returns a chi2-value of 926 and a p-value of 0.000.

Now, recoding the dependent variable as:

recode rep77 (1=5) (2=4) (4=2) (5=1), gen(rep77_2)

and running

ologit rep77_2 foreign

oparallel, brant

returns a chi2-value of -3396 and a p-value of 1.000.

This surely has a perfectly reasonable explanation, but i wonder if someone would care to explain to me exactly what is going on here?