Warner’s Randomized Response Technique

E I py p y

( ) ( )( ) ( ) ( ) ,

= + − − = − + −

1 1 1 2 1

leading to r I p pi i= − − −[ ( )]/( )1 2 1 and ER(ri) = yi. Again, since I Ii i2 = and y yi i2 = ,

V I E I E I

p p

V r p p

( ) ( )( ( )) ( ),

( ) ( )

= − = −

= = −

1 1

1 and hence

Vi ( ) .