“…In general, certain groups, such as males (Curtin, Presser & Singer, 2000;Groves & Couper, 1996;Moore & Tarnai, 2002;Singer, van Hoewyk & Mather, 2000), and individuals with low incomes (Curtin et al, 2000;Goyder, 1986;Goyder, Warriner & Miller, 2002;Groves, Singer & Corning, 2000;Kandel & Raveis, 1983;Singer, Groves & Corning, 1999), are less likely to respond to surveys than females and individuals with high incomes. Research has also shown that the response rate for the old is lower than for the young (Goyder, 1986;Kaldenberg, Koenig & Becker, 1994;Kandel & Raveis, 1983;Lowe & McCormack, 1955;Moore & Tarnai, 2002) and that in the United States Blacks are less likely to complete surveys than Whites (Curtin et al, 2000;Groves et al, 2000;Singer et al, 1999;Singer et al, 2000;Voigt, Koepsell, & Daling, 2003). In general, independent of the demographic group under consideration, potential survey participants are more likely to respond to surveys if they have an interest in the topic under study (Filion, 1975;Kojetin, Borgida & Snyder, 1993;Pearl & Fairley, 1985;Stinchcombe, Jones & Sheatsley, 1981;Van Kenhove, Wijnen & De Wulf, 2002).…”