Richard Austen-Baker (Letters, June 18) complains that I haven't answered his question about the purpose of the National Statistics Socio-economic Classification.
I thought I had made it clear that it can help us understand how social position affects life chances.
For example, using it we can show that men in class 1 (higher managers and professionals) have a life expectancy seven years longer than men in class 7 (routine occupations). Or that for 20 to 64-year-olds, men in class 7 are 2.5 times more likely to die from heart disease than higher managers in class 1.
The equivalent ratios for strokes, cancer, accidents and suicide are, respectively, 3.6, 2.2, 4.1 and 5.3. Equivalent class patterns can be shown for other aspects of life chances.
Faced with these regularities, the social scientist will try to show why they exist and what governments might do to reduce their impact.
And Austen-Baker is the muddled one if he thinks my statement that people in the same occupation could be in different classes from each other means that the same person can simultaneously be in any number of classes.
However, unlike many occupations, schoolteachers are an example of a group that are all placed in the same NS-SEC class.
David Rose
Essex University