What are the quality impacts of conducting high profile official statistical collections on a voluntary basis?

The article reviews several articles including "Producing official statistics via voluntary surveys " the National Household Survey in Canada" by by Marc Hamel and Normand Laniel, "The Impact of Non-response on Survey Quality" by Jelke Bethlehem and Bart Bakker and "Voluntary and Volunteer Surveys in US" by Phil Kott are presented.