Not really. People have all sorts of biases that will come out when self-reporting. Things which carry a positive connotation, or that a person is proud of, w

Not really. People have all sorts of biases that will come out when self-reporting. Things which carry a positive connotation, or that a person is proud of, will be over-reported. Things that are viewed negatively will be under-reported. Things which are embarrassing or controversial will be skewed as well. If if was random, normally distributed error, then the errors would cancel out. However, many questions will be biased in one direction, not randomly around a true median.