The article discusses how researchers have been studying returns to scale in the transport industry in a more detailed way. They are trying to figure out how to measure the increase in output of transport companies more accurately. By including factors like network size and output characteristics, they can better understand how costs change with different levels of output. For example, in the airline industry, the length of flights and how full the planes are can affect costs. This research helps us understand how transport companies can become more efficient as they grow.