What was the significant impact of the Airline Deregulation Act of 1978?

The Airline Deregulation Act of 1978 had a transformative effect on the structure of the airline industry in the United States. The primary impact of this legislation was that it removed market entry barriers for airlines, allowing for a more competitive environment. Prior to the act, the government tightly regulated which airlines could enter the market, what routes they could operate, and the fares they could charge.

By removing these restrictions, the act enabled new airlines to enter the market, fostering competition that often led to lower fares and a wider range of services for consumers. This shift encouraged innovation and improved customer service as airlines vied for business in a less regulated marketplace. Additionally, deregulation allowed carriers to adjust their routes based on market demands rather than adhering to government-imposed limits, which further enhanced operational flexibility.

In contrast, the options regarding subsidies, regulatory oversight for fares, and increased government control suggest a continuation of previous regulatory practices, which the act aimed to dismantle. Thus, the correct answer reflects the core intent and outcome of the Airline Deregulation Act.