lnfdi = natural log of foreign direct investment.
lngrp = natural log of gross regional product.
lnawg = natural log of average wage employed persons in urban units.
op = openness measured as sum of export and import divided by GRP.
inf = inflation measured as consumer price index annual change of region.
infr = infrastructure index measured as composite index of number of fixed telephone subscribers, number of internet
subscribers and length of paved road.
agg = agglomeration calculated as no. of industrial enterprises per GRP.
coa = dummy variable where in region in coastal area taking value 1, 0 otherwise