6,513 research outputs found
Fair Influence Maximization: A Welfare Optimization Approach
Several behavioral, social, and public health interventions, such as
suicide/HIV prevention or community preparedness against natural disasters,
leverage social network information to maximize outreach. Algorithmic influence
maximization techniques have been proposed to aid with the choice of "peer
leaders" or "influencers" in such interventions. Yet, traditional algorithms
for influence maximization have not been designed with these interventions in
mind. As a result, they may disproportionately exclude minority communities
from the benefits of the intervention. This has motivated research on fair
influence maximization. Existing techniques come with two major drawbacks.
First, they require committing to a single fairness measure. Second, these
measures are typically imposed as strict constraints leading to undesirable
properties such as wastage of resources.
To address these shortcomings, we provide a principled characterization of
the properties that a fair influence maximization algorithm should satisfy. In
particular, we propose a framework based on social welfare theory, wherein the
cardinal utilities derived by each community are aggregated using the
isoelastic social welfare functions. Under this framework, the trade-off
between fairness and efficiency can be controlled by a single inequality
aversion design parameter. We then show under what circumstances our proposed
principles can be satisfied by a welfare function. The resulting optimization
problem is monotone and submodular and can be solved efficiently with
optimality guarantees. Our framework encompasses as special cases leximin and
proportional fairness. Extensive experiments on synthetic and real world
datasets including a case study on landslide risk management demonstrate the
efficacy of the proposed framework.Comment: The short version of this paper appears in the proceedings of AAAI-2
Fairness Behind a Veil of Ignorance: A Welfare Analysis for Automated Decision Making
We draw attention to an important, yet largely overlooked aspect of
evaluating fairness for automated decision making systems---namely risk and
welfare considerations. Our proposed family of measures corresponds to the
long-established formulations of cardinal social welfare in economics, and is
justified by the Rawlsian conception of fairness behind a veil of ignorance.
The convex formulation of our welfare-based measures of fairness allows us to
integrate them as a constraint into any convex loss minimization pipeline. Our
empirical analysis reveals interesting trade-offs between our proposal and (a)
prediction accuracy, (b) group discrimination, and (c) Dwork et al.'s notion of
individual fairness. Furthermore and perhaps most importantly, our work
provides both heuristic justification and empirical evidence suggesting that a
lower-bound on our measures often leads to bounded inequality in algorithmic
outcomes; hence presenting the first computationally feasible mechanism for
bounding individual-level inequality.Comment: Conference: Thirty-second Conference on Neural Information Processing
Systems (NIPS 2018
A Moral Framework for Understanding of Fair ML through Economic Models of Equality of Opportunity
We map the recently proposed notions of algorithmic fairness to economic
models of Equality of opportunity (EOP)---an extensively studied ideal of
fairness in political philosophy. We formally show that through our conceptual
mapping, many existing definition of algorithmic fairness, such as predictive
value parity and equality of odds, can be interpreted as special cases of EOP.
In this respect, our work serves as a unifying moral framework for
understanding existing notions of algorithmic fairness. Most importantly, this
framework allows us to explicitly spell out the moral assumptions underlying
each notion of fairness, and interpret recent fairness impossibility results in
a new light. Last but not least and inspired by luck egalitarian models of EOP,
we propose a new family of measures for algorithmic fairness. We illustrate our
proposal empirically and show that employing a measure of algorithmic
(un)fairness when its underlying moral assumptions are not satisfied, can have
devastating consequences for the disadvantaged group's welfare
Preference-Informed Fairness
We study notions of fairness in decision-making systems when individuals have
diverse preferences over the possible outcomes of the decisions. Our starting
point is the seminal work of Dwork et al. which introduced a notion of
individual fairness (IF): given a task-specific similarity metric, every pair
of individuals who are similarly qualified according to the metric should
receive similar outcomes. We show that when individuals have diverse
preferences over outcomes, requiring IF may unintentionally lead to
less-preferred outcomes for the very individuals that IF aims to protect. A
natural alternative to IF is the classic notion of fair division, envy-freeness
(EF): no individual should prefer another individual's outcome over their own.
Although EF allows for solutions where all individuals receive a
highly-preferred outcome, EF may also be overly-restrictive. For instance, if
many individuals agree on the best outcome, then if any individual receives
this outcome, they all must receive it, regardless of each individual's
underlying qualifications for the outcome.
We introduce and study a new notion of preference-informed individual
fairness (PIIF) that is a relaxation of both individual fairness and
envy-freeness. At a high-level, PIIF requires that outcomes satisfy IF-style
constraints, but allows for deviations provided they are in line with
individuals' preferences. We show that PIIF can permit outcomes that are more
favorable to individuals than any IF solution, while providing considerably
more flexibility to the decision-maker than EF. In addition, we show how to
efficiently optimize any convex objective over the outcomes subject to PIIF for
a rich class of individual preferences. Finally, we demonstrate the broad
applicability of the PIIF framework by extending our definitions and algorithms
to the multiple-task targeted advertising setting introduced by Dwork and
Ilvento
The Measure and Mismeasure of Fairness: A Critical Review of Fair Machine Learning
The nascent field of fair machine learning aims to ensure that decisions
guided by algorithms are equitable. Over the last several years, three formal
definitions of fairness have gained prominence: (1) anti-classification,
meaning that protected attributes---like race, gender, and their proxies---are
not explicitly used to make decisions; (2) classification parity, meaning that
common measures of predictive performance (e.g., false positive and false
negative rates) are equal across groups defined by the protected attributes;
and (3) calibration, meaning that conditional on risk estimates, outcomes are
independent of protected attributes. Here we show that all three of these
fairness definitions suffer from significant statistical limitations. Requiring
anti-classification or classification parity can, perversely, harm the very
groups they were designed to protect; and calibration, though generally
desirable, provides little guarantee that decisions are equitable. In contrast
to these formal fairness criteria, we argue that it is often preferable to
treat similarly risky people similarly, based on the most statistically
accurate estimates of risk that one can produce. Such a strategy, while not
universally applicable, often aligns well with policy objectives; notably, this
strategy will typically violate both anti-classification and classification
parity. In practice, it requires significant effort to construct suitable risk
estimates. One must carefully define and measure the targets of prediction to
avoid retrenching biases in the data. But, importantly, one cannot generally
address these difficulties by requiring that algorithms satisfy popular
mathematical formalizations of fairness. By highlighting these challenges in
the foundation of fair machine learning, we hope to help researchers and
practitioners productively advance the area
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