  In online crowdsourcing labour markets, employers decide which job-seekers to
hire based on their reputation profiles. If reputation systems neglect the
aspect of time when displaying reputation profiles, though, employers risk
taking false decisions, deeming an obsolete reputation to be still relevant. As
a consequence, job-seekers might be unwarrantedly deprived of getting hired for
new jobs and can be harmed in their professional careers in the long-run. This
paper argues that exposing employers to the temporal context of job-seekers'
reputation leads to better hiring decisions. The visible temporal context in
reputation systems helps employers to ignore a job-seeker's obsolete
reputation. An experimental lab study with 335 students shows that current
reputation systems fall short of making them aware of obsolete reputation. In
contrast, graphical time cues improve the social efficiency of hiring
decisions.
