blp: BLP contraction mapping

In choicer: Discrete Choice Models for Economic Applications

BLP contraction mapping

Description

Finds the ASC (delta) parameters such that predicted market shares match target shares, using the contraction mapping of Berry, Levinsohn, and Pakes (1995) \Sexpr[results=rd]{tools:::Rd_expr_doi("10.2307/2171802")}.

Usage

blp(object, target_shares, ...)

Arguments

object	A fitted model object.
target_shares	Numeric vector of target market shares (length J).
...	Additional arguments passed to methods.

Value

Converged delta (ASC) vector.

Examples

library(data.table)
set.seed(42)
N <- 50; J <- 3
dt <- data.table(id = rep(1:N, each = J), alt = rep(1:J, N))
dt[, `:=`(x1 = rnorm(.N), x2 = rnorm(.N))]
dt[, choice := 0L]
dt[, choice := sample(c(1L, rep(0L, J - 1))), by = id]
fit <- run_mnlogit(dt, "id", "alt", "choice", c("x1", "x2"))
blp(fit, target_shares = rep(1/J, J))

choicer documentation built on Sept. 5, 2026, 1:07 a.m.