The definition from Wikipedia about multi-valued treatment is quite ambiguous to me, is there any other simpler definition or intuitive example for this term?
1$\begingroup$ If you cannot tell what it is you find "non-intuitive" how exactly are people supposed to help you? As it is this is very low effort question. $\endgroup$– bomadsenJun 28, 2021 at 16:08
In a standard treatment effects set up there are only two options to compare: Either the subject is treated or the subject is non-treated.
Multi-valued treatment happens when subjects are not only treated but potentially treated in different ways. If there are two pills people can eat they can either eat one or the other or none (assuming eating both is disallowed by construction). In that case there are two treatments and one non-treatment.
Multi-valued treatment can also be ordinal. Assuming one pill is a higher dose of the same than the other pill, then individuals taking the high dose pill are treated 'more' than those who take low dose pill.
Finally, treatment can be continuous when the medicine in the pills are given in continuous sized dose here there are uncountably many potential treatment values.
$\begingroup$ The current 2-part vaccines are a multi-value treatment. One can get: 0 vaccines, 1 vaccine, 2 vaccines. Each has its own level of effect on COVID. $\endgroup$ Jun 28, 2021 at 16:34
$\begingroup$ Yes, sure. How does that add anything not already included in the answer? $\endgroup$ Jun 28, 2021 at 16:49
1$\begingroup$ It's an exact, current example as opposed to a general, hypothetical one. That's why I added it as a comment. $\endgroup$ Jun 28, 2021 at 16:53
$\begingroup$ Fair point .... $\endgroup$ Jun 28, 2021 at 16:55