Do you pay more in taxes if you have two jobs vs one job or Is there a financial reason why one forty hr full time job would pay more than two part time twenty hour jobs at the same pay rate?

Do you pay more in taxes if you have two jobs vs one job or Is there a financial reason why one forty hr full time job would pay more than two part time twenty hour jobs at the same pay rate?
The issue between having one job or two has less to do with the actual pay as it does with taxes. For instance, if you have one job that pays you $20,000 a year and another that pays you $10,000. Each job will withhold taxes at those pay rates. What happens then at the end of the year is your taxes will be figured based on the combined income of $30,000. You may find yourself owing taxes. So before taking a second or a part time job consider the tax consequences and try to figure that in to your withholding/exemptions so you end the year more or less even with the IRS.