Sellin and Wolfgang (1964) drew attention to the enormous range of activities that can be classified as robbery, which can occur in homes and varied types of business premises as well as on the street. Dividing robbery into commercial and personal, it is generally accepted that there is high reporting of commercial robbery. Skogan (1976) quotes a rate of 86 per cent and Parisi et al. (1979), one of 90 per cent. However, for personal robbery, rates appear to be much lower, e.g. Skogan (1976) gives 49 per cent and Hough and Mayhew (1983) 47 per cent. This latter survey provides a reminder of the relative scarcity of the offence by pointing out (again for personal robbery only) that a ‘statistically average’ person aged sixteen or over can expect a robbery (not attempts), once every five centuries. It has been customary to regard robbery as a property offence (Letkemann 1973; Conklin 1972; Capone and Nichols 1976) and in America it shows a high inter correlation with burglary (Brantingham and Brantingham 1984; 279). Studies using regression modelling, correlation and canonical analysis show the following factors to be strongly related to it:

City size (Brantingham and Brantingham 1980)

City density (Harries 1976; Shichor et al. 1979; Worden 1980)

Ethnicity (Harries 1976; Worden 1980)

Unemployment (Worden 1980)

Percentage of household heads who are female (Harries 1976)