Zusammenfassung:
This study examines the impact of infrastructure development on intra-WAMZ trade, with a comparative assessment of the effects of different infrastructure categories on trade flows among member states. A modified gravity model, employing the Poisson pseudo-maximum likelihood (PPML) estimation technique, is utilised to ensure reliable results and achieve the study's objectives. The study covers all six member states of the Zone over the period 2005 to 2023. Findings reveal that while overall infrastructure development exhibits a positive relationship with intra-WAMZ trade, the effect is statistically insignificant. Similar outcomes are observed for energy and information technology infrastructure. Conversely, water and sanitation infrastructure demonstrates a statistically significant positive impact on trade within the Zone, whereas transport infrastructure exerts a negative and significant effect. These outcomes underscore persistent infrastructure gaps and highlight the need to improve infrastructure quality across the region. The significant positive coefficient for water and sanitation infrastructure suggests opportunities to enhance trade flows, particularly through addressing sanitary and phytosanitary (SPS) constraints. Accordingly, the study recommends intensified regional collaboration to overcome structural and policy barriers and improve infrastructure quality. Such efforts should aim to promote economic diversification, strengthen trade complementarities, and foster regional value chains, thereby advancing deeper integration, enhancing trade flows, and supporting sustainable economic growth.