Create "peace years" or "spells" by cross-sectional unit

sbtscs() allows you to create spells ("peace years" in the international conflict context) between observations of some event. This will allow the researcher to better model temporal dependence in binary time-series cross-section ("BTSCS") models.

Usage

sbtscs(data, event, tvar, csunit, pad_ts = FALSE)

Arguments

data: the data set with which you are working
event: some event (0, 1) for which you want spells or peace years
tvar: the time variable (e.g. a year)
csunit: the cross-sectional unit (likely a dyad if you're doing boilerplate international conflict stuff)
pad_ts: should time-series be filled when panels are unbalanced/have gaps? Defaults to FALSE.

Value

sbtscs() takes a data frame and returns the data frame with a new variable named spell.

Details

I should confess outright, and it should be obvious to anyone who looks at the code, that I liberally copy from Dave Armstrong's btscs() function in the DAMisc package. I offer two such improvements. One, the btscs() function chokes when a large number of cross-sectional units have no recorded "event." I don't know why this happens but it does. Further, "tidying" up the code by leaning on dplyr substantially speeds up computation. Incidentally, this concerns the same cross-sectional units with no recorded events that can choke the btscs() function in large numbers.

References

Armstrong, Dave. 2016. “DAMisc: Dave Armstrong's Miscellaneous Functions.” R package version 1.4-3.

Miller, Steven V. 2017. “Quickly Create Peace Years for BTSCS Models with sbtscs in stevemisc.” http://svmiller.com/blog/2017/06/quickly-create-peace-years-for-btscs-models-with-stevemisc/

Author

David A. Armstrong, Steven V. Miller

Examples

if (FALSE) { # \dontrun{
library(dplyr)
library(stevemisc)
data(usa_mids)

# notice: no quotes
sbtscs(usa_mids, midongoing, year, dyad)
} # }