At the lowest employment level, such as minimum wage, employers must pay a flat payroll tax per employee that 'they're hiring. To alleviate this burden, employers are trying to reduce the wages they pay their employees. Since employers cannot reduce the amount they pay their employees at the minimum wage level, they end up reducing the number of employees they hire. This is called “salary shifting.” Crucially, payroll taxes at this level cannot be transferred to minimum wage earners, because their wages cannot be lowered to a level that offsets the burden of the tax. This poses a problem for low-wage workers trying to find work, because hiring places a burden on employers that they are not willing to pay. In conclusion, the difference between payroll taxes and income tax is who ends up paying that tax. Employers pay social security contributions, while employees pay income tax. Wage displacement occurs when employers attempt to shift the burden of payroll taxes onto employees. However, at the minimum wage level, employers can no longer lower wages and end up hiring less.