You obviously do not know anything about RRSP's. The last time I looked the contribution limit was based on 18% of your earned income.....the maximum contribution is somewhere around $22,000 to 24,000 this year.

an RRSP account can have almost any investment vehicle not interest alone

your question makes not sense at all....if it is a course question I would have serious reservations about that course.

RRSPs allow ppl to shelter some of their income from taxation. Suppose the maximum annual contribution changes from $5000 to $8000 per person. How would the demand and supply curves shift?

Would real interest rate increase or decrease, what about investment spending?