Advantages of official statistics are that they are likely to involve a much larger sample than a sociologist could ever achieve (often referring to the entire target population rather than a sample of it) and it is free and accessible, so therefore practical.

A disadvantage of official statistics, and all secondary sources, is that the data was collected by somebody else for a different reason and the researcher has no control over the original data collection. Furthermore, official statistics can be manipulated for the government's political advantage (e.g. trying to make it look as though unemployment levels are falling by changing how the data is calculated).