The randomized response technique is applied on a voluntary basis for
estimating the purchase of smuggled liquor in Norway. Of a total sampl
e of 2330 respondents, aged 15 and over, about one half chose the prot
ective option of the RR-technique. The other half responded directly t
o the supposed sensitive questions. The estimates from the two groups
were weighted together to give population estimates for the percentage
of buyers, and the quantities bought, of smuggled liquor. The resulti
ng estimates were found to be considerably higher than estimates from
a contemporary survey based on direct response only.