Financial markets don’t usually trade on court rulings alone. But new research argues that investors also price in something more basic: the ideological tilt of the U.S. Supreme Court, and what that tilt could imply for the economy years down the line.
In a study by economists Thomas Drechsel and Naixin Zhang, the authors examine whether shifts in the Court’s ideological balance alter market expectations about key macroeconomic outcomes. Their central idea is that the Supreme Court can influence the policy environment—especially fiscal policy—through decisions that shape what elected officials can do and what regulatory paths are likely to survive legal challenge. If investors believe the Court’s composition affects future policy, they may quickly update forecasts for inflation, growth, and interest rates.
To isolate cause and effect, Drechsel and Zhang use a quasi-experimental strategy: unexpected deaths of Supreme Court justices. Such events can abruptly change, or be expected to change, the Court’s ideological center. Because these deaths are sudden, the authors treat them as plausibly unanticipated shocks that allow for cleaner inference than ordinary political news.
The researchers then track high-frequency movements in asset prices around these events to infer how expectations shift in real time. The pattern they document is consistent and directional. When the Court becomes more conservative, markets respond as if they anticipate weaker inflation and softer real economic activity. At the same time, bond yields decline. When the expected ideological balance moves in a more liberal direction, markets exhibit the opposite behavior: higher inflation expectations, stronger activity expectations, and rising yields.
A notable feature of the results is that inflation expectations and real-activity expectations move in the same direction. That co-movement matters for interpretation. If investors were primarily revising beliefs about the economy’s productive capacity or supply-side conditions, inflation and activity might be expected to move in opposite directions. Instead, the same-sign response suggests markets are updating beliefs about aggregate demand—how much spending power and stimulus the economy will receive.
The bond-market evidence points toward a specific mechanism. Drechsel and Zhang compare the yield changes they observe with estimates from prior research on how markets react to fiscal-policy news. This comparison implies that investors interpret a more conservative Supreme Court as increasing the likelihood of tighter fiscal policy in the future, while a more liberal Court is read as raising the odds of looser fiscal policy. In other words, traders appear to treat Court ideology as information about whether the policy mix ahead will be more contractionary or expansionary.
To bolster the credibility of their quasi-experimental approach, the authors also look at sector-level asset price behavior. They report high-frequency reactions in industries that are especially sensitive to government policy and legal risk, including clean energy and health care. Those sectoral moves help validate that the market is indeed responding to perceived changes in the policy landscape tied to Court composition, rather than to unrelated macro news.
The study, circulated through the National Bureau of Economic Research, credits Sarah Zubairy for discussions and notes feedback from audiences at forums including the Midwest Macro Meetings, Insightful Minds in International Macro, and George Washington University. The authors also emphasize that the analysis reflects their views, not necessarily those of the NBER.
Why it matters
Supreme Court turnover is often framed as a cultural and legal turning point, but this research suggests it may also be an economic signal that moves expectations in markets within minutes. Investors, policymakers, and households could all be affected if judicial ideology shapes beliefs about future fiscal expansion or austerity. The next question to watch is whether similar market reactions appear around other institutional changes that alter the perceived boundaries of economic policy.