RE: re:RSP...The percentage (%)of income tax increases as taxable income increses.
By contributing to an RRSP you are lowering your taxable income so you are paying less tax in dollars and a lower percentage on the that amount.
If you do make the contribution the percentage is higher and the amount of taxable income is higher.
When takeing money out of the RRSP the money becomes taxable but the thought is that the amount of income being reported is less and therefore the percentage charged is less resulting in paying less income tax.
IT would be counter productive to withdraw from an RRSP in a year that normal income is reported. RRSP's are designed for withdrawals in retirement years when income is generally lower.