diff --git a/R/ukhls_combine_hhold_smokers.R b/R/ukhls_combine_hhold_smokers.R
index 38cb189..e48983d 100644
--- a/R/ukhls_combine_hhold_smokers.R
+++ b/R/ukhls_combine_hhold_smokers.R
@@ -22,7 +22,7 @@ ukhls_combine_hhold_smokers <- function(data = NULL) {
   hhold <- hhold[, `NA` := NULL]
   hhold <- hhold[, non_smoker := NULL]
   hhold <- hhold[, smoker := NULL]
-  data <- merge(data, hhold, by = "hidp")
+  data <- suppressWarnings(suppressMessages(merge(data, hhold, by = "hidp")))
 
   return(data)
 }
diff --git a/R/ukhlsclean.R b/R/ukhlsclean.R
index 3d7d183..ff37ebe 100644
--- a/R/ukhlsclean.R
+++ b/R/ukhlsclean.R
@@ -194,6 +194,10 @@ data <- ukhlsclean::ukhls_combine_waves(data_list)
 ### Summation of smokers in household
 data <- ukhls_combine_hhold_smokers(data)
 
+#####################################
+### Lag household smokers to (t-1)
+data <- data[order(pidp, wave_no), lag.s_hhold_smokers := data.table::shift(s_hhold_smokers, n=1, type="lag"), by=pidp]
+
 ###################################
 ### Combine youth data