Oil Price Lag: Why Gas Prices Don’t Drop Instantly

When crude oil prices fluctuate, a structural pattern often emerges at the gasoline pump: prices tend to rise rapidly but descend at a slower pace. This phenomenon, colloquially known as the “rocket and feather” effect, has once again drawn the attention of policymakers, with US President Donald Trump ordering a Justice Department investigation into major oil companies this Wednesday.

President Trump articulated his concern on Truth Social, stating, “The big Oil Companies are not dropping their price at the pump commensurate with the sharply lower prices they are paying for Oil. Those prices are dropping like a rock! In other words, customers are being ‘gouged’.” He further instructed the DOJ to “immediately start looking into this,” demanding that “Gasoline prices better start going down a lot faster than what I’m seeing!”

From a first-principles perspective, the disconnect between falling crude prices and slower-to-drop retail gasoline prices is not necessarily evidence of malfeasance, but rather a reflection of the complex supply chain and market dynamics at play. Gasoline is not simply crude oil; it is a refined product with multiple cost components beyond the raw commodity itself.

The journey from crude oil to your vehicle’s tank involves extraction, transportation, refining, distribution, and finally, retail sales. Each stage carries its own costs, including labor, infrastructure, and regulatory compliance, which remain relatively fixed regardless of crude price movements. Furthermore, taxes constitute a significant portion of the final pump price, adding another layer of stickiness.

A critical factor in the lag is inventory. Refineries and distributors purchase crude oil and gasoline inventory at prevailing market prices. When crude prices fall, retailers are often still selling gasoline that was produced from higher-priced crude stock. This inventory turnover mechanism means it takes time for lower raw material costs to filter through to the consumer.

Moreover, the competitive landscape at the retail level can influence pricing behavior. While intense competition might drive prices down quickly in some areas, the perception of falling crude prices can also lead retailers to hold margins for a period to recover previous losses or optimize profitability after a period of volatility. President Trump noted on Tuesday that the average price of gasoline nationwide had decreased by $0.60 a gallon “just from a short while ago,” with prices dropping below $4 per gallon last week, a first since March.

This drop followed a memorandum of understanding between the US and Iran aimed at ending their conflict and restoring shipping through the Strait of Hormuz, suggesting a broader market response to geopolitical developments. However, the President’s directive underscores the public’s expectation for immediate and proportional price adjustments, a dynamic that rarely aligns with the inherent lags of a multi-stage commodity market.

Understanding these underlying mechanisms—from inventory cycles to fixed operating costs and retail market behavior—is crucial for interpreting the observed divergence. While the investigation will focus on specific company practices, the structural pattern of how crude oil costs translate to pump prices offers a broader lens through which to view these market reactions.