V.2 Data
For this empirical analysis, we use data on manufacturing employment at the district level from the General Population Census of Cambodia for 1998 and 2008.14 But we restrict our data set to samples that are available for both 1998 and 2008. Table 3 shows the number of frontier districts in Cambodia (the total number of districts in Cambodia is 185). Five districts are dropped, since the census for 1998 was not conducted in these districts, among which are four districts bordering Thailand.'3 In addition, the border post in Preah Vihear is excluded because it was closed due to a territorial dispute between Cambodia and Thailand. Summary statistics are provided in Table 4. Provincial GDP and geographical information on the districts have been obtained from the Cambodian National Institute of Statistics. To construct road variables and frontier region dummies, we used the document titled “Cambodia Road Network Map” published by the Ministry of Public Works and Transport.