There is no official data on region-to-region trade flows between different countries within the European Union (EU). Due to this limitation, several important questions regarding the dynamics of EU integration remain unanswered, both for researchers and policymakers. The recent withdrawal of the United Kingdom from the EU, for example, has highlighted this deficit. As a result, researchers were unable to study the asymmetric impacts of BREXIT on regional economies. Similarly, the COVID19 pandemic, and the way in which countries and regions moved to quickly restrict cross-border movements on public health grounds, further demonstrates how important it is to understand trade flows and how they are impacted when exposed to sudden shocks.

The aim of the ESPON IRIE project (Interregional Relations in Europe) is to address this deficit by generating new data and evidence about interregional economic and social relations across the EU. As an interim complement to this pan-European analysis, this Working Paper examines the interregional-international trade of Spain with France and Portugal with a level of fine-grain detail that has never been applied before, covering the NUTS 3 spatial level (provinces) and the period 2004-2018.

Some notes to consider when reading this paper:

• We estimate the optimal routes more likely used by the trucks, identifying the core nodes in the transport network, and the regions that are crossed in each delivery, something required to estimate possible spillovers and externalities.
• In the context of COVID19, routing the flows helps to anticipate disruptions in the supply chain due to restrictions to mobility.
• On average, the flows are positively related to the size of the trading regions and inversely with their accessibility. Singular sectoral linkages are also identified, which are explained by some key firms operating in a region.
• The results show the different nature of the French and the Portuguese borders, and how the conclusions are affected by the spatial scale used in the analysis.
• We also measure how after several years promoting the European Single Market, the Spanish regions trade 13 times more with other Spanish regions than with the ones of France and Portugal, something that is line with previous findings measuring the integration between the United States and Canada.

More details and updates on the IRIE project.