As per our TurboTax article:
Understanding Pension Income Splitting for Seniors, If you receive a larger pension than your spouse or common-law partner, it may be beneficial to transfer over a portion of your income on your tax return. This technique reduces your taxable income by shifting a portion to the lower-earning partner, thus reducing your overall tax burden as a retired couple or household. Splitting the pension income is a right think to do because of the benefit stated above (that must have changed your refund). You may split the pension income with your wife up to 50% of your pension.