Table 5.

Identified factors, theme 4: trade

Theme	Factor	References	Expected impact towards a Direct Connection
Trade	Colonial ties	Biermann (2012), Saeed et al. (2020)	±
	Common language	Saeed et al. (2020)	−
	Connectivity	Chang et al. (2020), Hoffmann et al. (2020), Saeed et al. (2020), Wilmsmeier and Martínez-Zarzoso (2010)	+
	Logistics performance	Chang et al. (2020)	+
	Nautical distance	Biermann (2012), Guerrero et al. (2015), Saeed et al. (2020)	−
	Port infrastructure	Biermann (2012), Bottasso et al. (2018), Hummels and Schaur (2013)	+
	Trade agreement	Biermann (2012), Chang et al. (2020), de Benedictis and Tajoli (2011), Prokopowicz and Berg-Andreassen (2016)	+
	Trade facilitation	Bertho et al. (2016), Biermann (2012), Hummels and Schaur (2013)	+
	Trade flow	Bertho et al. (2016), Guerrero et al. (2015)	+
	Trade imbalance	Bertho et al. (2016), Wilmsmeier and Martínez-Zarzoso (2010)	−
	Transit time	Hummels and Schaur (2013)	−
	Voyage cost	Deardorff (1998)	−