Berthelon (2004) indicates that the size of a partner’s market influences a country’s
growth prospects. In general, the larger a core RTA market is, the faster export growth
of its member countries will be. Now that EurAsEC is the most successful integration
organization in the region, a country’s increased export volume after joining the EurAsEC
is set as the indicator of function of core RTA. GDPEt indicates the economy of scale of
EurAsEC, and GDPit indicates the gross domestic product (GDP) of country i. Hence,
INTit measures the effect of integration on exports of country i when it joins EurAsEC.