“It is true that a spouse is not automatically entitled to increases of spousal support when the other spouse’s post-separation income increases: Thompson v. Thompson, 2013 ONSC 5500 (CanLII), at para. 103. The same principle should apply to a one-time increase. Unlike the Child Support Guidelines, there is no express statutory authority for imputation of income: Mann v. Mann, 2009 CanLII 23874 (ON SC), at para 15. The Divorce Act, s. 15.2(4), does not refer to income but, rather, to “means.”
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The logic that dictates a predictable stream of income as a measure of a payor spouse’s “means” would also suggest that a temporary increase should not be used to boost the support if a temporary decrease would not be grounds for lowering it. Moreover, in the case of post-separation income increases, the authors of the SSAG stated, in s. 14.3, that the principles of spousal support militate against increasing support, especially if the marriage was not long:
There are two possible formulaic extremes here. At one extreme, one could decide that any post-separation income increase of the payor spouse should not affect the amount of spousal support. After all, some would suggest, the recipient is entitled to a sharing of the marital standard of living, but no more. Certainly, this bright-line method would be predictable and administratively simple. At the other extreme, one could argue that the formulas should just continue to be applied to any income increase for the payor. This again would offer a predictable result, but one which the basic principles of spousal support would not justify in all cases. This approach is most compelling after a long traditional marriage.”