% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/planning.R
\name{mb_counterfactual}
\alias{mb_counterfactual}
\title{Define a counterfactual}
\usage{
mb_counterfactual(
  definition,
  source = c("rct", "quasi-experimental", "theory-based", "comparator", "historical"),
  credibility = NA_character_
)
}
\arguments{
\item{definition}{Character scalar describing the counterfactual:
what would have happened in the absence of the policy.}

\item{source}{Character scalar. Mechanism by which the
counterfactual is constructed. One of \code{"rct"},
\code{"quasi-experimental"}, \code{"theory-based"}, \code{"comparator"},
\code{"historical"}.}

\item{credibility}{Character scalar. Plain-English assessment of
how credible the counterfactual is.}
}
\value{
An \code{mb_counterfactual} object.
}
\description{
Records the comparison condition against which the policy effect
is to be measured. The Magenta Book stresses that no impact
evaluation is possible without an explicit counterfactual.
}
\examples{
mb_counterfactual(
  definition  = "Eligible non-applicants in the same year",
  source      = "quasi-experimental",
  credibility = "Moderate; selection on observables only"
)
}
\references{
HM Treasury (2020). The Magenta Book: Central Government
Guidance on Evaluation, supplementary guidance on
quasi-experimental and theory-based methods.
\url{https://www.gov.uk/government/publications/the-magenta-book}.
}
\seealso{
\code{\link[=mb_evaluation_plan]{mb_evaluation_plan()}}.

Other planning: 
\code{\link{mb_balance_table}()},
\code{\link{mb_evaluation_plan}()},
\code{\link{mb_questions}()},
\code{\link{mb_stakeholders}()}
}
\concept{planning}
