Sharpen your pencil and grab a calculator because it's math time!

Group A:

First, add up the following expenses for the back-to-work spouse:

• What is the dollar cost of the commute? (gas, bus, train, additional insurance, wear & tear on car, pick up from daycare, etc.) 
• Accessories: briefcase, office supplies, home office, etc. 
• Food: lunches with coworkers, schmoozing, drinks, coffee runs, etc. 
• Wardrobe and grooming 
• Exhaustion-induced dinners: pizza, Chinese, Burger King, etc. 
• Work related seminars, networking conventions, trade organization memberships, etc. (anything not reimbursed) 
• Health expenses: marital counseling, personal trainer, medication, etc. 
• Total yearly cost of children's daycare

Group B:

Now consider the following:

• What do you expect will be your combined total household income? 
• What is your combined taxable income? 
• What is the federal tax on the combined income? 
• What is the state and local tax on the new income? 
• How much Social Security is withheld from the new income? 
• What are your total deductions? 
• What is your childcare credit? 
• What is the new income's net after taxes?

Many people are surprised to find that the extra income earned by the back-to-work parent increases their tax liability to a large extent with the remainder eaten up by all the new expenses that working full time outside the home entails. Some people even come up with a deficit!