#' Public Opinion on Abortion Across U.S. States
#'
#' @description
#' This dataset examines the relationship between public opposition to abortion
#' and demographic, religious, and socioeconomic characteristics across the
#' 50 U.S. states and the District of Columbia. The response variable is a
#' proportion bounded in the (0,1) interval, making the data suitable for
#' simplex regression and beta regression analyses.
#'
#' @docType data
#' @usage data(AbortionOpposition)
#'
#' @format A data frame with 51 observations and 9 variables:
#' \describe{
#'   \item{state}{Factor. U.S. state or the District of Columbia.}
#'   \item{abortion_opposition}{Numeric. Proportion of adults who believe
#'         abortion should be illegal in all or most cases, bounded in the
#'         (0,1) interval, based on the Pew Research Center 2023--24
#'         Religious Landscape Study. This is the response variable used
#'         in the regression analyses.}
#'   \item{religious_attendance}{Numeric. Percentage of adults who report
#'         attending religious services at least once a week, based on the
#'         Pew Research Center 2023--24 Religious Landscape Study.}
#'   \item{income}{Numeric. Mean household income (in U.S. dollars) in 2024.}
#'   \item{sex_ratio}{Numeric. Number of males per 100 females in 2024.}
#'   \item{female}{Numeric. Proportion of the population that is female,
#'         bounded in the (0,1) interval, in 2024.}
#'   \item{pop_18_24}{Numeric. Percentage of the population aged 18--24 years,
#'         obtained directly from the 2024 American Community Survey (ACS)
#'         1-Year Estimates (Table S0101).}
#'   \item{bachelors}{Numeric. Percentage of adults aged 25 and older with a
#'         bachelor's degree or higher, in 2024.}
#'   \item{urban}{Numeric. Percentage of the population living in urban areas,
#'         based on 2020 U.S. Census Bureau estimates.}
#' }
#'
#' @details
#' The dataset was assembled by the package authors from multiple publicly
#' available sources. The response variable, \code{abortion_opposition},
#' was obtained from the Pew Research Center 2023--24 Religious Landscape
#' Study and rescaled to the (0,1) interval.
#'
#' The explanatory variables were obtained as follows:
#' \enumerate{
#'   \item \code{religious_attendance} was obtained from the Pew Research Center
#'         2023--24 Religious Landscape Study.
#'   \item \code{income} and \code{sex_ratio} were obtained from
#'         World Population Review using U.S. Census Bureau estimates.
#'   \item \code{female} was derived from \code{sex_ratio} and is provided
#'         on the (0,1) proportion scale, unlike the other percentage-based
#'         explanatory variables in this dataset, which are on the 0--100
#'         scale. Note that \code{sex_ratio} and \code{female} are
#'         mathematically related (\code{female = 100 / (100 + sex_ratio)})
#'         and should generally not be included together as covariates in
#'         the same regression model, as doing so would introduce
#'         near-perfect collinearity.
#'   \item \code{pop_18_24} corresponds to the percent estimate of the
#'         population aged 18--24 years reported directly in Table S0101
#'         (Age and Sex) of the 2024 American Community Survey (ACS)
#'         1-Year Estimates.
#'   \item \code{bachelors} was obtained from World Population Review
#'         using U.S. Census Bureau estimates for 2024.
#'   \item \code{urban} was obtained from World Population Review and is
#'         based on 2020 U.S. Census Bureau data, the most recent Census
#'         estimate of urbanization by state available at the time this
#'         dataset was compiled. All other explanatory variables in this
#'         dataset reflect 2023--24 estimates.
#' }
#'
#' @source
#' Pew Research Center. 2023--24 Religious Landscape Study.
#'
#' Pew Research Center (2025). Americans' Views on Abortion Differ by State.
#'
#' World Population Review (2024). Per Capita Income by State
#' (Mean Household Income 2024 column).
#'
#' World Population Review (2024). Male to Female Ratio by State.
#'
#' World Population Review (2024). Educational Attainment by State
#' (Bachelors or Higher 2024 column).
#'
#' World Population Review (2020 U.S. Census data). Most Urban States
#' (Urban Population Pct 2020 column).
#'
#' U.S. Census Bureau. American Community Survey (ACS) 1-Year Estimates (2024),
#' Table S0101: Age and Sex.
#'
#' @keywords datasets
#'
#' @examples
#' # Load the data
#' data(AbortionOpposition)
#'
#' # Quick overview
#' head(AbortionOpposition)
#' str(AbortionOpposition)
#'
#' # Summary statistics
#' summary(AbortionOpposition)
#'
#' # Relationship between religious attendance and abortion opposition
#' plot(abortion_opposition ~ religious_attendance,
#'      data = AbortionOpposition,
#'      pch = 19,
#'      xlab = "Religious attendance (%)",
#'      ylab = "Abortion opposition (proportion)")
#'
#' # Correlation among numeric variables
#' cor(AbortionOpposition[, c("abortion_opposition",
#'                         "religious_attendance",
#'                         "income",
#'                         "sex_ratio",
#'                         "female",
#'                         "pop_18_24",
#'                         "bachelors",
#'                         "urban")])
"AbortionOpposition"
