When users can benefit from certain predictive outcomes, they may be prone to act to achieve those outcome, e.g., by strategically modifying their features. The goal in strategic classification is therefore to train predictive models that are robust to such behavior. However, the conventional framework assumes that changing features does not change actual outcomes, which depicts users as "gaming" the system. Here we remove this assumption, and study learning in a causal strategic setting where true outcomes do change. Focusing on accuracy as our primary objective, we show how strategic behavior and causal effects underlie two complementing forms of distribution shift. We characterize these shifts, and propose a learning algorithm that balances between these two forces and over time, and permits end-to-end training. Experiments on synthetic and semi-synthetic data demonstrate the utility of our approach.

翻译：当用户能够从某些预测结果中获益时，他们可能倾向于采取行动以促成这些结果，例如通过策略性修改其特征。因此，战略分类的目标是训练对此类行为具有鲁棒性的预测模型。然而，传统框架假设改变特征不会改变实际结果，这暗示用户是在“操纵”系统。本文摒弃了这一假设，研究实际结果确实会改变的战略因果情境中的学习问题。以准确性为首要目标，我们展示了策略行为与因果效应如何构成两种互补形式的分布偏移。我们刻画了这些偏移，并提出一种能够在这两种力量间取得平衡、适应时间变化且支持端到端训练的学习算法。在合成数据和半合成数据上的实验证明了我们方法的有效性。