Why do companies in the Philippines fire staff every 3 months.

The Philippines has some very strong employment laws and rules which often means that companies try to avoid people gaining rights to them. This is why you will often see large corporate companies changing their staff every 3 months to stop people gaining employment rights. Also during a training period you can also pay people below the minimum wage and I know from people in the call centre industry some people were getting paid as low as P40 a day that only just covered the commute to the training.