This function creates lagged choice covariates from the data.frame
choice_data
, which is assumed to be sorted by the choice occasions.
Arguments
- choice_data
A
data.frame
of choice data in wide format, i.e. each row represents one choice occasion.- column
A character, the column name in
choice_data
, i.e. the covariate name. Can be a vector.- k
A positive number, the number of lags (in units of observations), see the details. Can be a vector. The default is
k = 1
.- id
A character, the name of the column in
choice_data
that contains unique identifier for each decision maker. The default is"id"
.
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).