In a labor market in which firms offer tied hours-wage packages and
there is substantial dispersion in the wage offers associated with a
particular type of job, the best job available to a worker at a point in
time may pay well but require an hours level which is far from the worker's
labor supply schedule, or pay poorly but offer desirable hours.
Intuitively, one would expect hours constraints to influence the pattern of
wage-hours tradeoffs which occur when workers quit to new jobs. Constrained
workers may be willing to sacrifice wage gains for better hours. Likewise,
workers may accept jobs offering undesirable hours only if the associated
wage gains are large. We investigate this issue empirically by examining
whether overemployment (underemployment) on the initial job increases
(reduces) the partial effect on the wage gain of a positive change in hours
for those who quit. We also examine whether overemployment
(underemployment) on the new job increases (reduces) the partial effect on
the wage gain of a positive change in hours for those who quit. Despite the
limitations imposed by small sample sizes and lack of information on the
magnitude of hours constraints, our results support the view that an
individual requires compensation to work in jobs which, given the
individual’s particular preferences, offer unattractive hours.

The paper examines how hours constraints affect the decision to change
jobs and the patterns of hours-wage tradeoffs which result from job changes.
We analyze job mobility in a labor market in which work hours on a given job
are inflexible and it is costly for workers to locate and move to alternative
jobs. Costs of mobility and imperfect information about job offers will
prevent a worker from adjusting hours by costlessly moving to jobs which offer
wage—hours combinations on the his or her labor supply schedule.
Consequently, workers will trade off wage gains for hours adjustments in
making job changes. Specifically, we show that the partial effect of a
positive change in hours by job changers who were overemployed (underemployed)
on their prior job is to increase (reduce) the size of the wage gain required
to induce a quit. The partial effect of a positive change in hours by job
changers who are overemployed (underemployed) on their new job is to increase
(reduce) the size of the wage gain associated with the quit.
We test these propositions through an empirical study of the relationship
between the wage change and interactions among the change in hours and
indicators of overemployment and underemployment on the old job and the new
job. Despite the limitation imposed by small sample sizes and lack of
information on the magnitude of hours constraints, our results are supportive
of the theory.

This paper provides evidence that hours of work are heavily influenced by
the particular job which a person holds. The empirical work consists of a
comparison of the variance in the change in work hours across time intervals
containing a job change with the variance in the change in hours across time
periods when the job remains the same. To the extent that workers choose
hours and these hours choices are influenced by shifts in individual
preferences and resources, the variance in the time change of hours should not
depend upon whether the worker has switched jobs. The desire to reduce or
increase hours could be acted upon in the current job. On the other hand, if
hours are influenced by employer preferences or if job specific
characteristics dominate the labor supply decision, then hours changes should
be larger when persons change jobs than when they do not. Using the Panel
Study of Income Dynamics and the Quality of Employment Survey, we find that
hours changes are two to four times more variable across jobs than within
jobs. This result holds for both men and women, is obtained for weeks per
year, hours per week, and annual hours, and is not sensitive to the use of
controls for a set of job characteristics (including the wage) which might
influence the level of hours persons wish to supply.
The finding that the job has a large influence on work hours suggests
that much greater emphasis should be given to demand factors and to job
specific labor supply factors in future research on hours of work. The
overwhelming emphasis upon the wage and personal characteristics in
conventional labor supply analyses of work hours may in part be misplaced.

If hours can be freely varied within jobs, the effect on hours of
changes in preferences for those who do change jobs should be similar to
the effect on hours for those who do not change jobs. Conversely, if
employers restrict hours choices, then changes in preferences should affect
hours more strongly when the job changes than when it does not change. For a
sample of married women we find that changes in many of the labor supply
preference variables produce much larger effects on hours when the job
changes.