Opening the Interregional Trade ‘‘Black Box’’: The C-Intereg Database for the Spanish Economy (1995—2005)

Recent literature on border effect has demonstrated that national trade (intra- as well as interregional trade) tends to be more intense than international trade. Unfortunately, owing to the dearth of information on interregional economic relations, this important aspect of the economy has remained relatively ignored. In this article, the authors have described the methodology and main results of the largest estimation of Spanish interregional trade (1995—2005) carried out as a part of the C-Intereg project. The results obtained highlight the importance of the internal trade and the validity of the gravity model. Although the estimation focuses on the Spanish economy, the methodology can easily be applied to other European Union (EU) countries. In the upcoming years, this innovative database will be further developed in all its dimensions (space, time, and sectors) to serve as a promising framework for the application of different techniques such as spatial interaction models or interregional input—output approaches.