See https://book.declaredesign.org/observational-causal.html#difference-in-differences
Usage
lag_by_group(x, groups, n = 1, order_by, default = NA)
Arguments
- x
Vector of values
- groups
Grouping variable
- n
Positive integer of length 1, giving the number of positions to lead or lag by
- order_by
Ordering variable withing group (e.g., time)
- default
Value used for non-existent rows. Defaults to NA.
Value
vector of lagged values