  Crowdsourcing has evolved as an organizational approach to distributed
problem solving and innovation. As contests are embedded in online communities
and evaluation rights are assigned to the crowd, community members face a
tension: they find themselves exposed to both competitive motives to win the
contest prize and collaborative participation motives in the community. The
competitive motive suggests they may evaluate rivals strategically according to
their self-interest, the collaborative motive suggests they may evaluate their
peers truthfully according to mutual interest. Using field data from Threadless
on 38 million peer evaluations of more than 150,000 submissions across 75,000
individuals over 10 years and two natural experiments to rule out alternative
explanations, we answer the question of how community members resolve this
tension. We show that as their skill level increases, they become increasingly
competitive and shift from using self-promotion to sabotaging their closest
competitors. However, we also find signs of collaborative behavior when
high-skilled members show leniency toward those community members who do not
directly threaten their chance of winning. We explain how the individual-level
use of strategic evaluations translates into important organizational-level
outcomes by affecting the community structure through individuals' long-term
participation. While low-skill targets of sabotage are less likely to
participate in future contests, high-skill targets are more likely. This
suggests a feedback loop between competitive evaluation behavior and future
participation. These findings have important implications for the literature on
crowdsourcing design, and the evolution and sustainability of crowdsourcing
communities.
