The number of North Korean employees working at apartment-style factories in the Gaesong Industrial Complex has jumped to about 35-hundred, an increase of almost 50 percent in less than four months.

The industrial park had roughly 23-hundred workers when 32 companies entered the zone in October.

Officials at the complex cited low employment costs as a reason for the rapid increase. With monthly wages of only 60 dollars per month, North Korean workers cost 20 to 40 dollars less than workers from China. Moreover, Chinese workers provide fewer tax benefits and are subject to stiffer regulations.