Francisco Arizala, Mr. Matthieu Bellon, Ms. Margaux MacDonald, Mr. Montfort Mlachila, and Mustafa Yenice
After close to two decades of strong economic activity, overall growth in sub-Saharan Africa decelerated markedly in 2015–16 as the largest economies experienced negative or flat growth. Regional growth started recovering in 2017, but the question remains of how trends in the economies stuck in low gear will spill over to the countries that have maintained robust growth. This note illuminates the discussion by identifying growth spillover channels. The focus is on trade, banking, financial, remittance, investment, fiscal, and security channels, which are the most prominent and most likely to transmit growth trends across borders. In addition to bringing together findings from a broad array of existing research, the note identifies countries that are the most likely sources of regional spillovers and those that are most likely to be impacted, and provides estimates for the size of these channels. It finds that intraregional trade and remittance flows are an important channel for growth spillovers, while banking channels are less important but will remain a risk going forward. Finally, the note documents other important spillover channels through financial markets contagion, revenue-sharing arrangements in fiscal unions, commodity-pricing policies, corporate investment, and forced migration. The main takeaway is that the level of interdependence among sub-Saharan countries is higher than is generally assumed. Consequently, there is a need for additional emphasis on regional surveillance and spillover analysis, along with traditional bilateral surveillance.
We present a gravity model that accounts for multilateral resistance, firm heterogeneity and country-selection into trade, while accommodating asymmetries in trade flows. A new equation for the proportion of exporting firms takes a gravity form, such that the extensive margin is also affected by multilateral resistance. We develop Taylor approximated multilateral resistance terms with which to capture the comparative static effects of changes in trade costs. For isolated bilateral changes in trade frictions, multilateral resistance effects are small for most countries. However, if all countries reduce their trade frictions, the impact of multilateral resistance is so strong that bilateral trade falls in most cases, despite the larger trade elasticities implied by firm heterogeneity. As a consequence, the world-wide trade response, though positive, is much lower.