Derivation
variable: egcook_mode (table[s]: NCD_combined_data_all_final [derived table])
variable: felect (table[s]: caps_blhse)
variable: flpg (table[s]: caps_blhse)
gen egcook=0 if felect==0 & flpg==0 /*What fuel is regularly used to cook food at your home?*/
replace egcook=1 if felect==1 | flpg==1