Short-term absence from industry. 3. The interfence of 'proneness' and a search for causes.

297-312. The abilities of five hypotheses (chance', proneness', and three of true contagion' - as defined in the text) to explain the distributions of one-day and two-day absences among groups of male and female industrial personnel and clerks in government service are examined by curve-fitting and correlation methods. The five hypotheses generate (in order) the Poisson, negative binomial, Neyman type A, Short, and Hermite (two-parameter form) distributions which are fitted to the data using maximum-likelihood estimates. The conclusion is drawn that proneness', i.e., a stable liability', compounded from several though unquantifiable factors, and constant for each individual over the period of the study, is markedly successful in explaining the data. It is emphasized that some of the other hypotheses under test cannot be unequivocably rejected; and there is in theory an infinite number, still unformulated or untested, which may be acceptable or even fit the data better. Correlation coefficients for the numbers of one-day (and two-day) absences taken by the same individuals in two equal non-overlapping periods of time are of the order 0·5 to 0·7 (0·3 to 0·5 for two-day absences) and the corresponding regressions fulfil linear requirements. These correlations are higher than any between personal characteristics' and their overt consequence in contingent fields of human enquiry. For one-day absences the predictive power for the future from the past record could in some circumstances justify executive action. When freely available, overtime was greatest among junior married men and least among junior married women. The validity of the inference of `proneness' and the implications of its acceptance are fully discussed. While interpretation is not unequivocal, one-day absences seemingly have many causes; two-day absences are also heterogeneous but in some ways resemble longer certified absence. It is concluded that short-term absence, particularly of one day, may be largely the overt expression of a traditional desire, even need, to work discontinuously which, though it can be mitigated by often identifiable general and individual circumstances, is consistently more marked in some individuals than in others.