Twenty years of airport efficiency and productivity studies: A machine learning bibliometric analysis

Airport efficiency and productivity analysis has attracted increasing attention over the last two decades. During this period, the number of such studies has grown significantly, with more than 100 articles related to the topic having been published in peer-reviewed journals in broad areas including transportation, economics, manage-ment, operations research and mathematics. Our study complements the previous literature surveys by adopting bibliometric analysis to improve the understanding of airport efficiency and productivity studies. Our analysis identifies publication patterns (e.g., the most relevant authors, institutions and countries; collaborative networks; key journals; and the most cited articles) and popular research topics (e.g., keyword analysis). The annual growth rate of publications is found to be 10.96%, with an increasing trend during 1999-2019. In terms of geographical distribution, almost half of the studies evaluate the performance of the airport sector in Europe, while 21.88% focus on Asian airports. Airport ownership form and size, hub status and economic regulations are popular variables used to explain variation in airport efficiency.