BUYDOWN Statement
BUYDOWN options ;

The BUYDOWN statement specifies a buydown rate loan. The buydown rate loans are similar to ARM loans, but the interest rate adjustments are predetermined at the initialization of the loan, usually by paying interest points at the time of loan initialization.

You must use all the required specifications and options listed under the FIXED statement with the BUYDOWN statement. The following option is specific to the BUYDOWN statement and is required:

BUYDOWNRATES=( date1=rate1 date2=rate2 ... )

BUYDOWNRATES=( period1=rate1 period2=rate2 ... )
BDR=

specifies pairs of periods and the predetermined nominal interest rates that will be charged on the loan starting at the corresponding time periods.

You can also specify the buydown periods as dates in the form of SAS date literals if you also specify the date of the initial payment by using a date value in the START= option. Buydown periods (or dates) and the respective buydown rates must be in time sequence.