Establishing causation for a complex societal issue requires more than a single data set. The best approach is to build a "collage of evidence." This involves finding natural experiments—like states that enacted a policy before a national ruling—to test the hypothesis under different conditions and strengthen the causal claim.

Alex Boris passed a bill requiring mopeds to be registered at the point of sale. When data showed total registrations subsequently declined, he publicly admitted the policy missed the real issue: owners weren't re-registering after a year. This demonstrates a rare political willingness to use data to admit failure and iterate on policy.

Despite public support for the death penalty being at a 50-year low, executions in America have surged. This is primarily because the conservative-leaning Supreme Court has ceased its former practice of issuing last-minute stays, effectively giving states a green light to proceed with executions without federal oversight or intervention.

The 'Right to Try' Act fundamentally changed end-of-life care dynamics. For patients who have failed standard treatments, it transfers significant liability from the physician to the patient, empowering doctors to pursue innovative, evidence-backed therapies without the same legal risk.

The dramatic decline in childhood peanut allergies offers a clear victory for public health policy. A 2015 reversal in official guidance—from avoidance to encouraging early exposure for infants—is directly credited with a 40% overall reduction, demonstrating how evidence-based policy can rapidly change health outcomes.

Grisham's most pragmatic argument against the death penalty isn't moral but systemic: Texas has exonerated 18 people from death row. He argues that even if one supports the penalty in principle, one cannot support a system proven to make catastrophic errors. This "flawed system" framework is a powerful way to debate high-risk policies.

The introduction of no-fault divorce laws was a legislative response to already-spiking divorce rates that were overwhelming the court system, rather than the cause of the increase. Data from states like California shows divorce rates were already rising before the law was changed and simply continued on the same trajectory afterward.

A new dynamic in the assisted dying debate involves the Democratic party strategically reframing the issue. Instead of a narrow medical or ethical question, they are positioning it as a fundamental "individual right," linking it to other core party values like reproductive and labor rights, thereby broadening its appeal and political momentum.

Instead of a single, premature federal AI mandate, a patchwork of state-level regulations creates a portfolio of experiments. This allows policymakers to learn what works in different populations (e.g., rural vs. urban) before establishing a more informed national framework.