Dredging the depths of knowledge: Efficiency analysis in the maritime port sector

- A dataset of port efficiency estimates from 52 previous studies is analyzed.
- The lack of attention paid to the user side of port services has important implications for interpreting efficiency estimates.
- We argue that a large portion of the applied methods do not capture substitution between supplier and user inputs.

Maritime port efficiency is a research area that has received considerable attention in recent years. While the accumulated empirical evidence concerning the drivers of port efficiency is large, there has not been any attempt at systematically assessing the causes of (in)efficiency through quantitative meta-analysis. This study therefore uses a compounded dataset of port efficiency estimates from 52 studies and regresses these estimates on port and country characteristics, while controlling for study-specific and methodological effects. Surveying the literature, we find that there is a lack of attention paid to the user side of port service production, which has crucial implications for the interpretation of efficiency estimates. At the cross-country level, we find a negative relationship between GDP per capita and estimated port efficiency, as well as a negative relationship between intra-port competition and estimated efficiency. We discuss the interpretation of these findings in the context of partial production functions, and argue that a large portion of the applied methods do not capture substitution between producer and user inputs. We also find that the ratio of military spending to GDP is positively related to estimated port efficiency, while a higher degree of product concentration in trade flows is associated with lower levels of estimated efficiency.