ct2df {DCchoice}

Convert a data frame in contingency-table format into a simple data frame of individual observations

Description

A convinience function converting a data frame object in contingency-table format of bid(s) and responses of dichotomous choice CV into a simple data frame of individual observations. The outcome is suitable for the analysis using functions in the package.

Usage

ct2df(x,
  bid1 = "bid1", bid2h = "bidh", bid2l = "bidl", bidl = "bidl", bidh = "bidh",
  nny = "nny", nnn = "nnn", yy = "yy", yn = "yn", ny = "ny", nn = "nn",
  y = "y", n = "n", n_y = "n_y", n_n = "n_n", nn_y = "nn_y", nn_n = "nn_n", 
  type = "double", spike = FALSE)

Arguments

x

a data frame object in contingency-table format containing bid(s) and responses

bid1

a character string showing the bid (for "single") or the bid in the first stage (for "double")

bid2h

a character string showing the second (higher) bid when respondents answer "Yes" in the first stage

bid2l

a character string showing the second (lower) bid when respondents answer "No" in the first stage

bidh

a character string showing the higher bid (for "oohb")

bidl

a character string showing the lower bid (for "oohb")

nny

a character string showing a number of respondents rejecting the first and the second bids and having a positive willingness-to-pay (WTP) (for a spike "double")

nnn

a character string showing a number of respondents rejecting the first and the second bids and having a zero WTP (for a spike "double")

yy

a character string showing a number of respondents accepting both the first and the second bids

yn

a character string showing a number of respondents accepting only the first bid

ny

a character string showing a number of respondents accepting only the second bid (for "double") or rejecting the first bid and having a positive WTP (for a spike "single")

nn

a character string showing a number of respondents rejecting the first and the second bids (for "double") or rejecting the first bid and having a zero WTP (for a spike "single")

y

a character string showing a number of respondents accepting the bid

n

a character string showing a number of respondents rejecting the bid

n_y

a character string showing a number of respondents rejecting the bid and having a positive WTP (for a spike "oohb")

n_n

a character string showing a number of respondents rejecting the bid and having a zero WTP (for a spike "oohb")

nn_y

a character string showing a number of respondents rejecting the first and second bids and having a positive WTP (for a spike "oohb")

nn_n

a character string showing a number of respondents rejecting the first and second bid and having a zero WTP (for a spike "oohb")

type

a character string setting the elicitation format, which takes one of "single" (single-bounded dichotomous choice format), "oohb" (one-and-one-half-bounded dichotomous choice format), or "double" (double-bounded dichotomous choice format)

spike

a logical code: TRUE for a spike model. The default is FALSE.

Details

The function ct2df implements a conversion of a data frame containing bid(s) and responses regarding dichotomous choice CV in contingency-table format into a data frame suitable for use by the functions sbchoice, oohbchoice, dbchoice, sbspike, oohbspike, dbspike, kristrom, turnbull.sb, and turnbull.db. See CarsonSB and CarsonDB for dataset in contingency-table format.

See the examples below and ones in spike-models, for usage in detail.

Value

The function returns a data frame, in which each row shows a single respondent. It contains the following variables.

For "single",

R1

a response to a bid: 1 for "Yes", 0 for "No"

bid1

the bid

For "double",

B1

a bid in the first stage

B2H

a (higher) bid in the second stage when the response is "Yes" in the first stage

B2L

a (lower) bid in the second stage when the response is "No" in the first stage

R

a combination of responses in the first and second stages, which takes yy for "Yes" and "Yes", yn for "Yes" and "No", ny for "No" and "Yes", or nn for "No" and "No"

R1

the response in the first stage, which takes 1 for "Yes", 0 for "No"

R2

the response in the second stage, which takes 1 for "Yes", 0 for "No"

bid1

the bid in the first stage

bid2

the bid in the second stage the respondent faced

For "oohb",

BH

a higher bid

BL

a lower bid

R

a combination of responses in the first and second stages

R1

the response in the first stage, which takes 1 if the bid is accepted, and 0 otherwise

R2

the response in the second stage, which takes 1 if the bid is accepted, 0 if the bid is not accepted, and -9 if the respondent has no second stage

For spike models,

S

the response in a simple spike question, which takes 1 if the respondent has a positive WTP, and 0 otherwise

References

Aizaki H, Nakatani T, Sato K (2014). Stated Preference Methods Using R. CRC Press, Boca Raton, FL.

See Also

sbchoice, oohbchoice, dbchoice, sbspike, oohbspike, dbspike, kristrom, turnbull.sb, turnbull.db

Examples

# Single-bounded dichotomous choice CV format
data(CarsonSB)
CarsonSB
CarsonSB.dat <- ct2df(
  x    = CarsonSB,
  bid1 = "T1",
  y    = "Y",
  n    = "N",
  type = "single")
head(CarsonSB.dat)
summary(turnbull.sb(R1 ~ bid1, data = CarsonSB.dat))

# Double-bounded dichotomous choice CV format
data(CarsonDB)
CarsonDB
CarsonDB.dat <- ct2df(
  x     = CarsonDB,
  bid1  = "T1",
  bid2h = "TU",
  bid2l = "TL",
  yy    = "yy",
  yn    = "yn",
  ny    = "ny",
  nn    = "nn",
  type  = "double")
head(CarsonDB.dat)
summary(turnbull.db(R1 + R2 ~ bid1 + bid2, data = CarsonDB.dat))