Is commission rebate to buyer outside closing taxable? If so, who should pay tax, real estate agent or buyer?

[leslie_weibi]

As a real estate agent, I normally rebate part of my commission to the buyer at closing.  However, there was one transaction this year that the seller did not allow that, so I gave the money back to the buyer outside of the closing.  For example, I received $3000 commission (on my 1099) and gave $1000 to buyer.  Can I deduct the $1000 as expense?  Is this $1000 taxable income?  If so, who should pay tax on it?

[Critter]

Read the answer here as it may be illegal in your state :   https://www.trulia.com/voices/Home_Buying/I_m_a_buyer_and_my_real_estate_agent_gave_me_a_p-278986