Create lagged choice covariates — create_lagged

This function creates lagged choice covariates from the data.frame choice_data, which is assumed to be sorted by the choice occasions.

Usage

create_lagged_cov(choice_data, column = character(), k = 1, id = "id")

Arguments

choice_data: [data.frame]
Choice data in wide format, where each row represents one choice occasion.
column: [character()]
Covariate names in choice_data.
k: [integer()]
The number of lags (in units of observations), see the details.
id: [character(1)]
The name of the column in choice_data that contains unique identifier for each decision maker.

Value

The input choice_data with the additional columns named column.k for each element column and each number k containing the lagged covariates.

Details

Say that choice_data contains the column column. Then, the function call


create_lagged_cov(choice_data, column, k, id)

returns the input choice_data which includes a new column named column.k. This column contains for each decider (based on id) and each choice occasion the covariate faced before k choice occasions. If this data point is not available, it is set to NA. In particular, the first k values of column.k will be NA (initial condition problem).

Examples

choice_data <- data.frame(id = rep(1:2, each = 3), cov = LETTERS[1:6])
create_lagged_cov(choice_data, column = "cov", k = 1:2)
#>   id cov cov.1 cov.2
#> 1  1   A  <NA>  <NA>
#> 2  1   B     A  <NA>
#> 3  1   C     B     A
#> 4  2   D  <NA>  <NA>
#> 5  2   E     D  <NA>
#> 6  2   F     E     D