GEKSdecomp:

#' Artificial prices of seasonal products Data created by R. Turvey
#'
#' The is dataset is presented in the ILO CPI manual. In 1979 Turvey sent his
#' artificial data set to statistical agencies around
#' the world, asking them to use their normal techniques to construct monthly
#' and annual average price indices. About 20 countries replied, and Turvey
#' summarized the responses as follows: ‘‘It will be seen that
#' the monthly indices display very large differences, e.g.,
#' a range of 129.12–169.50 in June, while the range of simple annual means
#' is much smaller. It will also be seen that the indices vary as to the
#' peak month or year.’’
#'
#' @format data frame with 176 rows and 4 variables
#' \describe{
#'   \item{month}{The time as a Date type}
#'   \item{commodity}{The seasonal product, as a factor
#'   (Apples, Grapes, Oranges, Peaches, Strawberries)}
#'   \item{price}{The price as numeric}
#'   \item{quantity}{The quantity of items sold in that month as an integar}}
#'
#' @source \url{https://www.ilo.org/wcmsp5/groups/public/---dgreports/---stat/documents/presentation/wcms_331153.pdf}
"turvey"