% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/discounting.R
\name{gb_npv}
\alias{gb_npv}
\title{Net present value}
\usage{
gb_npv(
  cashflow,
  years = NULL,
  schedule = "standard",
  base_year = NULL,
  vintage = "2022"
)
}
\arguments{
\item{cashflow}{Numeric vector of net cashflows in real terms (one
value per year).}

\item{years}{Integer vector of years matching \code{cashflow}. Defaults
to \verb{0, 1, ..., length(cashflow) - 1}.}

\item{schedule}{One of \code{"standard"}, \code{"health"}, \code{"catastrophic"}.}

\item{base_year}{Optional integer recording the price base year for
the cashflow (e.g. \code{2024}). Stored on the returned object.}

\item{vintage}{Character. Methodology vintage label. Defaults to
\code{"2022"}.}
}
\value{
A \code{gb_appraisal} object: a list with class
\code{c("gb_appraisal", "list")} and elements
\code{npv}, \code{cashflow}, \code{years}, \code{pv}, \code{schedule}, \code{base_year}, \code{vintage}.
}
\description{
Computes the net present value of a cashflow stream under the
Green Book STPR. Returns a \code{gb_appraisal} object carrying the NPV,
the input cashflow, the discount factors, the schedule used, and
methodology vintage.
}
\examples{
costs    <- c(100, 50, 50, 0, 0, 0, 0, 0, 0, 0)
benefits <- c(0, 0, 0, 30, 30, 30, 30, 30, 30, 30)
gb_npv(benefits - costs)
}
\references{
HM Treasury (2022). The Green Book, chapter on appraisal and the
Annex on discounting.
}
\seealso{
\code{\link[=gb_appraise]{gb_appraise()}}, \code{\link[=gb_eanc]{gb_eanc()}}, \code{\link[=gb_dist_weighted_npv]{gb_dist_weighted_npv()}},
\code{\link[=gb_carbon_npv]{gb_carbon_npv()}}.

Other discounting: 
\code{\link{gb_discount}()},
\code{\link{gb_discount_factor}()},
\code{\link{gb_eanc}()},
\code{\link{gb_stpr}()}
}
\concept{discounting}
