R/approval.R

In wooldridge: 115 Data Sets from "Introductory Econometrics: A Modern Approach, 7e" by Jeffrey M. Wooldridge

#' approval
#'
#' Wooldridge Source: Harbridge, L., J. Krosnick, and J.M. Wooldridge (forthcoming), “Presidential Approval and Gas Prices: Sociotropic or Pocketbook Influence?” in New Explorations in Political Psychology, ed. J. Krosnick. New York: Psychology Press (Taylor and Francis Group). Professor Harbridge kindly provided the data, of which I have used a subset. Data loads lazily.
#'
#' @section 
#'
#' Used in Text: 343, 371, 400
#'
#' @docType data
#'
#' @usage data('approval')
#'
#' @format A data.frame with 78 observations on 16 variables:
#' \itemize{
#'  \item \strong{id: }{id}
#'  \item \strong{month: }{month}
#'  \item \strong{year: }{year}
#'  \item \strong{sp500: }{S&P 500 index}
#'  \item \strong{cpi: }{Consumer Price Index}
#'  \item \strong{cpifood: }{CPI for food}
#'  \item \strong{approve: }{Gallup approval rate, percent}
#'  \item \strong{gasprice: }{average gas price, cents}
#'  \item \strong{unemploy: }{unemployment rate, percent}
#'  \item \strong{katrina: }{=1 for three months after Hurricane Katrina}
#'  \item \strong{rgasprice: }{real gas price, 100*(gasprice/cpi)}
#'  \item \strong{lrgasprice: }{log(rgasprice)}
#'  \item \strong{sep11: }{=1 for 09/2001 and two months following}
#'  \item \strong{iraqinvade: }{=1 for three months after Iraq invasion}
#'  \item \strong{lsp500: }{log(sp500)}
#'  \item \strong{lcpifood: }{log(cpifood)}
#' }
#' @source \url{http://www.cengage.com/c/introductory-econometrics-a-modern-approach-6e-wooldridge}
#' @examples  str(approval)
"approval"