There have been many tests of the convergence hypothesis yielding many different estimates of β (the speed of convergence). Narrative reviews of the convergence literature hint at possible reasons for the study-to-study variation in the value of β, but such reviews are selective and informal....

"This paper examines the impact of trade facilitation on intra-African trade. The authors examine the role of trade facilitation reforms, such as increased port efficiency, improved customs, and regulatory environments, and upgrading services infrastructure on trade between African countries....