The good effect is obviously more efficient work. There will be lesser errors since there will be no human errors. A robot can be programmed flawlessly and there will be very minimal mistakes in the job that the robot is doing. It will also be faster. Robots can also work non stop unlike humans.

The bad effect will be humans will become unemployed. Tons of people have a repetitive job and I remember the line "You will be replaced by a robot in the future." that is said to the people that are doing nothing but the same thing over and over again. An example of this are construction workers and factory workers. Robots can easily replace them and some of the tasks are already done by robots. The thing, though, robots require a lot of money. It will require bigger capital than just hiring people from the third world country. Since a lot of people in third world countries don't really specialize in something or too simply put it, they are uneducated, the payment for hard labor is a lot cheaper.