One explanation of differences in levels of illness and life expectancy is the artefact explanation. This explanation suggest that statistics shows an unfair prejudice towards lower class people because of high numbers of older and middle aged people working in dangerous jobs. It is likely for them to have higher level of ill health than those in higher classes that work in office jobs. It was expected that they would have higher levels of illness and mortality. This suggests that employment and age are also important factor when explaining the difference not just social class. The black report suggested that data between the high and lower classes is not accurate enough; it’s a result of the way the data is sourced and collected.