What is the main reason for losing respondents?
Refusals are much more common that the inability to find movers. Along with the refusals, another important reason is “no contact, nobody home during at least 3 visits”. We can only count refusals or no-contacts at the address of a previously interviewed household, but we almost never can say whether the same people were not home/refused, or whether the dwelling now has a new household. So it is difficult to differentiate between refusals and no-contacts.