Fairness Preferences, Actual and Hypothetical: A Study of Crowdworker Incentives

Angie Peng
Jeff Naecker
Nyalleng Moorosi
Proceedings of ICML 2020 Workshop on Participatory Approaches to Machine Learning (to appear)
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Abstract

How should we decide which fairness criteria or
definitions to adopt in machine learning systems?
To answer this question, we must study the fair-
ness preferences of actual users of machine learn-
ing systems. Stringent parity constraints on treat-
ment or impact can come with trade-offs, and
may not even be preferred by the social groups
in question (Zafar et al., 2017). Thus it might
be beneficial to elicit what the group’s prefer-
ences are, rather than rely on a priori defined
mathematical fairness constraints. Simply asking
for self-reported rankings of users is challenging
because research has shown that there are often
gaps between people’s stated and actual prefer-
ences(Bernheim et al., 2013).

This paper outlines a research program and ex-
perimental designs for investigating these ques-
tions. Participants in the experiments are invited
to perform a set of tasks in exchange for a base
payment—they are told upfront that they may
receive a bonus later on, and the bonus could de-
pend on some combination of output quantity and
quality. The same group of workers then votes on
a bonus payment structure, to elicit preferences.
The voting is hypothetical (not tied to an outcome)
for half the group and actual (tied to the actual
payment outcome) for the other half, so that we
can understand the relation between a group’s
actual preferences and hypothetical (stated) pref-
erences. Connections and lessons from fairness
in machine learning are explored.