DETROIT — General Motors' decision to switch from monthly to quarterly reporting of its U.S. sales could be the beginning of the end for a decades-old practice routinely used as a barometer of the industry's health.
The decision, which has raised questions about corporate transparency, marks the first significant change in auto sales reporting since the industry dropped 10-day reports in the early 1990s.
In announcing the change, GM explained that monthly sales figures were subject to many factors that make them more volatile than quarterly sales, including product launches, weather, other seasonal factors, the number of selling days and incentive activity.