Scott Alexander explores how straight-line trends on graphs might mask the true impact of interventions, using examples like the Clean Air Act and Moore's Law to illustrate the complexity of interpreting such data. Longer summary

Scott Alexander discusses the difficulty of interpreting trend lines on graphs, particularly when evaluating the effectiveness of interventions or policies. He uses examples like the Clean Air Act, OSHA's impact on workplace safety, and Moore's Law to illustrate how straight-line trends can persist despite significant interventions or technological advancements. The post suggests that these trends might be maintained by control systems, where various factors adjust to keep the trend consistent. This perspective complicates the assessment of policy effectiveness and technological impact, as their effects might be visible in other areas rather than directly on the graph. The author expresses uncertainty about how to distinguish between scenarios where interventions truly don't matter and those where they're part of a complex control system. Shorter summary