Benjamin(1958) collected data on the social mobility of some 2600 subjects using thirteen occupational categories.  Macdonald, used the index devised by Blau and Duncan (1967, p.43) to measure the dissimilarity in mobility between occupational groups. The measure, writes Macdonald (1972, pp.213-14) may be interpreted as  "the percentage of the sons of (group) A that would have to be reallocated jobwise for the sons of A to match the sons of B".  He assembles the index values into this lower diagonal matrix. 
REF: Macdonald, K.I. (1972) MDSCAL and distances between socio-economic groups, in K. Hope, ed The Analysis of Social Mobility Oxford: Clarendon Press
RUN NAME       OCCUPATIONAL DISSIMILARITY DATA
N OF STIMULI   13
DIMENSIONS     5 TO 1
PARAMETERS     DATA(1)
LABELS         FARMERS
               AGRICULTURAL WORKERS
               HIGHER ADMIN
               OTHER ADMIN
               SHOPKEEPERS
               CLERICAL WORKERS
               SHOP ASSISTANTS
               PERSONAL SERVICE
               FOREMEN
               SKILLED WORKERS
               SEMI-SKILLED WORKERS
               UNSKILLED WORKERS
               ARMED FORCES
READ MATRIX
51.1
71.4 75.8
63.0 52.7 36.9
58.6 57.7 40.8 32.3
67.0 55.6 38.6 17.7 38.2
63.4 52.3 39.4 13.4 27.8 27.3
54.5 43.3 55.5 29.3 41.1 35.0 23.5
71.2 47.5 56.5 26.2 41.0 35.6 21.1 36.1
65.2 44.3 62.3 33.0 45.1 42.1 27.4 32.0 14.7
65.7 43.0 68.2 39.0 50.8 47.3 33.3 36.0 15.7  8.4
60.1 34.2 69.4 39.8 51.9 47.2 35.5 30.4 23.9 21.1 19.3
66.7 41.9 62.7 36.1 44.6 42.7 29.0 35.9 21.2 20.7 18.4 18.9
PLOT               SHEP(2), STRESS(2), FINAL(2)
COMPUTE
FINISH