Question

In theory, why would an increase in minimum wage lead to an increase in the number of individuals who are unemployed?

Answer 1

Increase in minimum wage, will force firms to pat higher wages to the employees, but to offset the increased cost of labor, the firms will decrease the demand of labor in the market. So, more workers will remain either unemployed or laid off by the firms. As a result, there will be increase in the number of individuals who are unemployed.
Besides, with an increase in the minimum wage, firms try to hire individuals with superior technical skills and thee workers can do work with superior efficiency and productivity. It will also lead the more workers remain unemployed in the labor market.