Every few seconds at a factory here in Chongqing, a metal arm presses a laptop screen into the plastic shell of a computer. The rudimentary robot was introduced in November on some of Pegatron Corp.'s assembly lines in this western Chinese city. That the robot is here is testament to the increasing pressure on electronics manufacturers in China to automate as labor costs rise in the country. As the WSJ's Eva Dou reports:

Major municipalities in the country have raised minimum wages more than 10% annually in recent years. Shanghai's is now 1,820 yuan ($296) a month, compared with 960 yuan at the beginning of 2010. Assemblers...