Another broader model of work stress is Johannes Siegrist's
"effort-reward" model. The model defines threatening
job conditions as a "mismatch between high workload (high
demand) and low control over long-term rewards" (103, p.
1128). Siegrist emphasizes personal control over long-term reward
since "distressing experiences often result from basic threats
to the continuity of a crucial social role", among adults,
often the occupational role. This is clearly the case "with
job termination or job instability. However, related conditions
of low reward and low security may also be identified, such as
forced occupational change, downward mobility, lack of promotion
prospects, jobs held with inconsistent educational background
(status inconsistency)" (103, p. 1128). Components of workload
in Siegrist's research includes piecework, shiftwork, noise, work
pressure, and increase in workload.
In addition, a psychological component (the coping pattern or
"need for control") is added to the model. Two relevant
coping variables were identified from factor analysis -- "vigor",
a state of active efforts with a high probability of positive
feedback, and "immersion" a state of exhaustive coping
reflecting frustrated, but continued efforts and associated negative
feelings. "Immersion" is considered to increase an individual's
vulnerability to experiences of high demand and low status control.
In a prospective study of German factory workers, status inconsistency
(OR=4.4), job insecurity (OR=3.4), work pressure (OR=3.4), and
immersion (OR=4.5) independently predict CHD incidence after adjusting
for other behavioral and somatic risk factors (103). A combined
"low reward/high effort" variable is also a significant
predictor (OR=3.4) in a separate analysis.
While the "need for control" components ("vigor"
and "immersion") are considered to be "rather stable
person characteristics" in this model, it remains to be determined
to what extent they are influenced by levels of work control.
Several other studies provide some evidence for this process of
adult socialization. For example, in a U.S. study, the substantive
complexity of work (analogous to decision latitude) predicted
increased intellectual flexibility, non-authoritarianism, and
intellectually demanding leisure time 10 years later (66). In
Sweden, workers whose jobs became more "passive" (low
demand-low latitude) over six years reported less participation
in political and leisure activities. In contrast, workers in jobs
which became more "active", participated more in these
activities (58, p. 53).
An advantage of Siegrist's model is that it expands the concept
of control typically used in research on Karasek's job demands-control
model to include job security and upward mobility (promotion prospects).
However, a limitation of Siegrist's model is that it only predicts
effects of job conditions on CHD. It does not explicitly hypothesize
effects of job conditions on psychological functioning, motivation,
activity, learning and coping patterns.