The payroll tax in the United States is legally shared between the employee and the employer, with each paying 7.65% of wages. Using the supply and demand framework (graphical analysis), analyze the tax incidence and excess tax burden of this tax under the following scenarios:

• Labor supply is perfectly elastic.
• Both labor supply and labor demand are highly elastic.
• Labor supply is relatively inelastic and labor demand is relatively elastic.
• Labor supply is relatively elastic and labor demand is relatively inelastic.