Why Is It Important to Consider the Sources of Information

Why is it important to consider the sources of information on the distributions of incomes and wealth among Canadian families?

A) There are significant costs associated with the focus groups in which this data are collected.
B) It is only after in-depth qualitative interviews that informants provide reliable information.
C) Surveys are subject to sampling and non-sampling errors and these are especially important in wealth surveys.
D) Researchers have difficulty controlling for their biases in participant-observation studies of Canadian families.
E) Ethnographies of Canadian families raise important questions about confidentiality and anonymity when studying wealth.