Dear Statalisters,
I've been reviewing the manuals and statalist archives and I've
confirmed that Stata does not give any automatic warning message when
requirements for a valid chi-square test are not met (i.e. no more
than 20% of the expected values in a table are less than 5 and none
are less than 1), what I think is a nuisance. I suppose this can be
only worked out by writing the option 'expected' after tabulate and
checking oneself if the requirements are met. I believe Cox's tab-chi
package does give a warning when requirements are not met.
I wonder also if the Rao and Scott correction of Pearson chi-square
that is recommended for survey designs needs the same requirements.
The problem then would be that -svy:tab- doesn't support the
'expected' option neither tab-chi is suitable for survey analysis.
Best regards,
Angel Rodriguez-Laso
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