  Fairness, through its many forms and definitions, has become an important
issue facing the machine learning community. In this work, we consider how to
incorporate group fairness constraints in kernel regression methods, applicable
to Gaussian processes, support vector machines, neural network regression and
decision tree regression. Further, we focus on examining the effect of
incorporating these constraints in decision tree regression, with direct
applications to random forests and boosted trees amongst other widespread
popular inference techniques. We show that the order of complexity of memory
and computation is preserved for such models and tightly bound the expected
perturbations to the model in terms of the number of leaves of the trees.
Importantly, the approach works on trained models and hence can be easily
applied to models in current use and group labels are only required on training
data.
