Evaluation of transshipment productivity through the implementation of the Malmquist DEA method. Evidence from circular cargo handling in Polish seaports

This study evaluates the transshipment productivity of circular waste in six Polish seaports between 2013 and 2022 using the Malmquist Data Envelopment Analysis (DEA) method. The model is output-oriented and incorporates transshipped waste volumes as outputs, while inputs include quay length, maximum permissible draft, and maximum ship length. The results show that Gdynia achieved the highest productivity growth (+9.9%), followed by Darłowo (+2.8%) and Szczecin (+1%). In contrast, Świnoujście and Kołobrzeg experienced notable declines. Gdynia and Szczecin exhibited constant scale efficiency, while others suffered from scale disadvantages. Overall, total productivity increased slightly (+0.3%) over the decade, primarily due to technological change. Peaks in productivity in 2015 and 2020 correlated with significant technological improvements. These findings have practical policy implications: port authorities can benchmark their operations, identify inefficiencies, and tailor infrastructure investments to optimise the handling of circular waste. The results suggest that smaller, secondary ports – often overlooked in port research - can play a strategic role in circular supply chains if supported by proper planning and targeted modernisation. The application of Malmquist DEA in this novel cargo category and port group demonstrates the model’s potential for sustainable performance evaluation in complex logistics environments.