My wife told me I didn't explain myself clearly, so I'll try again.
Suppose that you and your neighbor were both eligible for a Child Tax Credit of $2,000. Would both you and your neighbor receive the same tax advantage from the credit? Not likely. I will give examples, and for simplicity's sake I will assume that no other tax credits apply. The Child Tax Credit (CTC) appears on line 51 of the 1040 Form and is included in the total credits which are shown no line 54. The tax return instructs filers to subtract Line 54 (total credits) from Line 46 (tax liability based on taxable income) and then record the difference on Line 55. Suppose your neighbor has an amount of taxable income which results in a tax liability of $5,000. Your neighbor would subtract the $2,000 credit from his tax liability of $5,000 and recorded the difference of $3,000 on line 55. If no other taxes were owed, this $3,000 would also appear on Line 61 which is the the total tax. If your neighbor had no credits, he would owe taxes of $5,000. But because of the CTC, your neighbor only has to pay taxes of $3,000; therefore, The CTC has given him the equivalent on $2,000 in the bank.
Now suppose you had no taxable income and the amount of tax you show on line 46 is zero. Could you enter the Child Tax Credit on Line 54 and subtract that amount from Line 46. No! No! No! The instructions on Line 55 clearly state: “Subtract line 54 from line 46.
If line 54 is more than line 46, enter -0-” (emphasis my own). Your credit can never by more than the tax which appears on line 46. If line 46 is zero, the CTC and all other non-refundable credits are worthless. Here is a link to the 1040 Form:
http://www.irs.gov/pub/irs-pdf/f1040.pdf?portlet=103
Additionally, the IRS Instructions make it very clear that you tax credit is limited by the amount that appears on Line 46 on the 1040 Form:
“You must reduce your child tax credit if the amount on Form 1040, line 46 is less than the credit. If this amount is zero, you cannot take this credit because there is no tax to reduce.” There are other factors which may reduce the CTC and they can be found at the following link:
Publication 972 (2011), Child Tax Credit
Refundable credits are different. They are treated as payments made to the IRS and are shown on lines 65-71 on the 1040 Form. A refundable credit of $2,000 is the same as $2,000 in the bank.
CONCLUSION: A tax cut of $2,000 is the same thing as getting $2,000 extra in your bank and applies to all taxpayers. A refundable credit of $2,000 is also the same as getting $2,000 in the bank, but not everyone is entitled to refundable credits. A non-refundable credit (such as the CTC) is unavailable to some taxpayers, and is limited by one's tax liability. A CTC or any other non-refundable credit of $2,000 could be worth up to $2,000 but it could be worth less, even zero. Another advantage of a tax cut over a tax credit is you don't need an instruction book to figure it out.
OK, my wife likes this much better, so now I'm done.