First lets define sweatshop:
The U.S. Government Accountability Office defines a sweatshop as an employer that violates more than one federal or state labor law governing minimum wage and overtime, child labor, industrial homework, occupational safety and health, worker's compensation or industry regulation.
So this the established rule for this country, in other countries it may vary depending on the nature of that countries government.
To answer the question.
Why did owners of sweatshops pay their workers piecework wages?
Answer:
To increase the individual productivity of each line worker, the more pieces assembled or completion of task the more money made, theoretically, but what if the company is dishonest and the accounting is different? Generally this type of exploitative environment would have accommodations, housing and store for instance, where the money made would go back to the company. The company would have it figured out by tracking productivity and it led to setting of threshold analysis (how much can a person in an age, or physical ability bracket can produce) so there would nearly always be, little or nothing left, leaving the employee in a slave like situation and in debt to the company.
Sweatshops are cheap to run. The workers are from very poor countries and they will work for extremely low wages. It is wrong to exploit people because they are so desperate for money and the conditions are horrible.
Food, wages, and discipline were provided for child workers.
Workers in sweatshops are treated brutally. They are not even allowed to take breaks or go toilet. They have very less wages even less than the minimum wage. They are aslo forced to work overtime or take the work home with them. Sometimes they are also left to starve
Many jobs could be done by unskilled workers for lower wages.
During the strikes many Union workers were paid higher wages while the Factory owners got nothing in return
many jobs could be done by unskilled workers who earned lower wages
They Want to save money wage is a cost of their company
many jobs could be done by unskilled workers who earned lower wages
The mill owners wanted big profits, so paid as little in wages as possible to their workers, who had little job security.
better conditions inside the sweatshops: heating/cooling workers working no more than 50 hours a week medical attention be included in their wage their wages should be ABOVE minimuim wage
This concept is part of the Scientific management theory ( Taylor). Taylor says that workers should be paid according to the amount of production (piecework). He realized that there were problems. Workers wanted to avoid having the piecework pay scale lowered. Therefore, a group of workers would often pressure each other to keep rate busting to a minimum. If productivity were kept down, wages would stay up. Based on: Miller, katherine. Organizational communication Approaches and Processes. 5th Ed. Boston, 2006. Chapter 2 p 25
not too sure about Nike now, but in normal sweatshops, workers have to endure long working hours (ie. 16-18hours a day), low wages (less than the minimum wage), no career breaks or holidays, often abused in many ways.