(CCWAEC). Similarly, trade costs would fall by 5.6 percent for the China‐Indochina Peninsula Economic Corridor (CICPEC) and by 21.6 percent for the China‐Central Asia‐West Asia Economic Corridor (CCWAEC). These large effects are not surprising given the importance of trade facilitation bottlenecks in BRI economies (Bartley Johns et al., 2018).

Our paper relates to several strands of literature. First, the importance of time as a trade barrier has been studied extensively in the literature and the heterogenous sensitivity of products to shipment delays has been documented in a number of papers including Hummels (2001), Hummels, Minor, Reisman, and Endean (2007), Djankov, Freund and Pham (2010), Hummels and Schaur (2013) and Baniya (2017). Second, several recent studies have analyzed the trade effects of infrastructure projects either within or across countries (Donaldson, 2018; Duranton, Morrow and Turner, 2014; Alder, 2017). Third, a subset of this literature also relies on georeferenced data and GIS analysis to assess the trade and the spatial effects of transport infrastructure (e.g. Roberts, Deichmann, Fingleton and Shi, 2010; Volpe Martincus, Carballo and Cusolito, 2017). By providing precise estimates of the potential decrease in trade costs expected from the Belt and Road Initiative, our databases are being used as inputs in papers assessing the potential implications of the BRI for trade flows, foreign investment, GDP and welfare (e.g. de Soyres, Mulabdic and Ruta, 2018; Baniya, Rocha and Ruta, 2018; Maliszewska, van der Mensbrugghe and Osorio‐Rodarte, 2018; Chen, 2018; Bird, Lebrand and Venables, 2018).

The paper is organized as follows. Section 2 presents the database on BRI transport projects and the methodology used to measure shipping times. Results of the network analysis are presented in Section 3, while the impact of the BRI on trade costs is analyzed in Section 4. Section 5 presents two extensions of the analysis. Concluding remarks follow.

# **2. Network analysis: Method and assumptions**

The Belt and Road Initiative covers a large number of transport projects in many countries. The consequences of implementing all those improvements is a priori very hard to forecast: for example, the benefit from building a new segment of rail might depend on the construction or upgrade of a new port at the end of the rail when joining the coast. Furthermore, the optimal route between two cities might depend on the implementation of several projects, which means that one cannot study transport infrastructures independently from one another. The interconnectedness of all elements in the transportation network poses a challenge to any researcher trying to estimate the changes in trade costs that can reasonably be gained from the BRI.

In order to embrace the complexity of network effects while at the same time taking into account all planned BRI transport projects and all countries in the world, our analysis is based on an estimation of shipping times. Specifically, our goal is to develop and implement a structured method to compute the shipping time between all city pairs in the world before the BRI and after the implementation of all identified BRI transport projects. This section presents our methodology and assumptions in detail.

## **a. Overall method**

As a starting point, we build a network model which takes into account in a precise way the current transportation network and we use it to compute shipment times between all city‐pairs using a shortest 4