% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/optimism_bias.R
\name{gb_optimism_bias}
\alias{gb_optimism_bias}
\title{Optimism bias upper bound for a project category}
\usage{
gb_optimism_bias(category, dimension = "capex")
}
\arguments{
\item{category}{Character. One of
\code{"standard_buildings"}, \code{"non_standard_buildings"},
\code{"standard_civil_engineering"},
\code{"non_standard_civil_engineering"},
\code{"equipment_development"}, \code{"outsourcing"}.}

\item{dimension}{Character. \code{"capex"} (default) for capital
expenditure uplift, or \code{"duration"} for works-duration uplift.}
}
\value{
Numeric scalar: the upper-bound percentage as a decimal
(e.g. 0.51 for 51 percent).
}
\description{
Returns the indicative upper-bound optimism bias percentage from
HM Treasury Supplementary Green Book Guidance: Optimism Bias
(Mott MacDonald 2002, Annex A1). The upper bound is the starting
value for ex-ante uplift; mitigation factors reduce it as project
definition matures through SOC, OBC, and FBC stages.
}
\examples{
gb_optimism_bias("non_standard_buildings")
gb_optimism_bias("standard_civil_engineering", dimension = "duration")
}
\references{
HM Treasury (2003). Supplementary Green Book Guidance: Optimism
Bias.

Mott MacDonald (2002). Review of Large Public Procurement in the
UK. Report commissioned by HM Treasury.
}
\seealso{
\code{\link[=gb_apply_ob]{gb_apply_ob()}}, \code{\link[=gb_categories]{gb_categories()}}, \code{\link[=gb_appraise]{gb_appraise()}}.

Other optimism bias: 
\code{\link{gb_apply_ob}()},
\code{\link{gb_categories}()}
}
\concept{optimism bias}
