Many people drive more carefully after receiving a traffic fine. But do large corporations, such as airlines, also change their behaviour when they face financial penalties? Researchers explored this question by examining penalties imposed on U.S. airlines for lengthy tarmac delays, asking whether fines genuinely deter misconduct or become another cost of doing business.

A tarmac delay occurs when an aircraft remains on the ground with passengers still on board for an extended period. U.S. regulations generally limit these delays to three hours for domestic flights and four hours for international flights, with airlines facing financial penalties for violations. However, when penalties are relatively small compared with an airline’s profits or the costs of preventing delays, they may be viewed as routine operating expenses rather than meaningful deterrents. Behavioural economics also suggests that small fines can unintentionally signal that rule-breaking is acceptable if the “price” is paid.

To determine whether penalties influence airline behaviour, the researchers focused on delays associated with severe weather, which airlines cannot fully predict or control. This approach enabled them to compare penalised and non-penalised airlines using statistical methods designed to estimate causal effects while minimising the influence of other operational differences.

The study found that penalties were associated with reductions in lengthy tarmac delays for some airlines, but the improvements were generally modest and often temporary. Other airlines responded in ways that differed from the regulation’s intended purpose, including increases in prolonged ground delays and higher rates of flight cancellations.

In ongoing research, the investigators are examining whether the size of the penalty influences airline responses. Preliminary findings suggest that greater reductions follow larger penalties in tarmac delays exceeding three hours, although these effects also appear to diminish over time. The researchers also found evidence that airlines may adjust their operations to remain just below the regulatory threshold, increasing very long ground delays that fall slightly short of the three-hour limit.

Overall, the findings suggest that simply increasing financial penalties is unlikely to produce consistent or lasting improvements in corporate behaviour. The researchers conclude that effective consumer-protection policies should consider not only the size of penalties, but also the durability of behavioural change and the potential for unintended consequences, such as increased flight cancellations or strategic responses to regulatory thresholds.

More information: Hideki Fukui et al, Penalties as prices? evaluating airline strategic responses to tarmac delay penalties in the US, Transportation Research Part A Policy and Practice. DOI: 10.1016/j.tra.2026.105063

Journal information: Transportation Research Part A Policy and Practice Provided by Ehime University