A lot of pathbreaking work (see recent Nobel Prize!) has focused on estimating the local average treatment effect (LATE). Two underappreciated points: LATE might not be the quantity you want; other causal quantities might be easier to describe when key assumptions fail. 1/N Angrist, Imbens & Rubin (1996) show LATE describes a very particular type of causal effect among “compliers,” those who accept/reject treatment, X, as instructed by encouragement, Z. This narrow focus is what makes the estimand “local.” 2/N