Hi ,

I have a variable of interest which is an indicator variable (LAW) that equals 1 if a firm is in a state having passed a certain law in that year and 0 otherwise.
(e.g., reghdfe DV LAW controls, absorb(sic2 fyear state) cluster(state)

gen LAW=state=="AZ" & fyear>2005|state=="AR" & fyear>2004|state=="CA" & fyear>1995|state=="CT" & fyear>2012|state=="DE" & fyear>1994|state=="FL" & fyear>1994|state=="GA" & fyear>1995|state=="HI" & fyear>2003|state=="IL" & fyear>2006|state=="IN" & fyear>1997|state=="KS" & fyear>2014|state=="LA" & fyear>1995|state=="ME" & fyear>1997|state=="MD" & fyear>2002|state=="MA" & fyear>1998|state=="MO" & fyear>2003|state=="NE" & fyear>1994|state=="NV" & fyear>1998|state=="NM" & fyear>2000|state=="NY" & fyear>1991|state=="OK" & fyear>2015|state=="OR" & fyear>2000|state=="PA" & fyear>1999|state=="RI" & fyear>1994|state=="TX" & fyear>2010|state=="TN" & fyear>1996|state=="UT" & fyear>2000|state=="VT" & fyear>2003|state=="WA" & fyear>2009 & fyear<2016|state=="MN" & fyear>1999 & fyear<2018


Thus, I would like to conduct some robustness tests that could randomize years and/or states to confirm that our results are not driven by spurious correlation.

Any suggestions on what tests or Stata commands I could use to conduct such analyses? Thank you in advance!