A quantitative analysis of historical market performance, fixed-income instruments, and the tax landscape for Alberta-based investors.
To determine whether to prioritize mortgage repayment or portfolio growth, an investor must first establish a baseline of expected returns. While mortgage interest is a guaranteed cost, investment returns are probabilistic. This manual outlines the historical performance of major asset classes, allowing for a direct comparison against current mortgage rates in the Edmonton region.
We utilize standardized risk metrics—including the Sharpe Ratio and Standard Deviation—to evaluate the efficiency of various capital allocation strategies. For a deeper understanding of how these figures impact interest over time, refer to our Mortgage Interest Calculation Manual.
Analysis of the S&P 500 and S&P/TSX Composite indices over 30-year horizons.
The historical average annual return for the S&P 500 (adjusted for dividends) has hovered near 10% before inflation. However, investors must account for the equity risk premium—the excess return over the risk-free rate.
VIEW RISK PROTOCOLS →The S&P/TSX Composite often exhibits higher concentration in energy and financials. Historical 20-year CAGRs for the TSX typically range between 6% and 8%, reflecting different sectoral risks compared to US markets.
REGIONAL STATS →For conservative Alberta investors, Guaranteed Investment Certificates (GICs) and Government Bonds serve as the primary alternative to mortgage prepayments. Unlike equities, these instruments offer predictable cash flows that can be directly mapped against mortgage amortization schedules.
"The decision to invest versus pay down debt is not merely a calculation of returns, but a management of cash flow volatility and tax liabilities."
Paper and Thatch Quantitative Research
In Alberta, interest income is taxed at your marginal rate. For high earners, a 5% GIC might only yield 3% after-tax, making mortgage prepayment significantly more attractive.
The Tax-Free Savings Account allows for 100% retention of gains. This is the primary vehicle where investment returns can realistically compete with debt reduction.
The immediate tax refund from RRSP contributions can be re-applied to mortgage principal, creating a powerful compounding effect. Detailed strategies are found in our Tax Efficiency Manual.
To find the break-even point, divide your mortgage interest rate by (1 - your marginal tax rate). If your mortgage is 5% and your tax rate is 30%, you need a 7.14% return in a taxable account to match the debt reduction benefit.
Historical data provides a range of outcomes but does not guarantee future performance. We recommend using a conservative 5-7% expected return for long-term equity planning to account for potential market stagnation.
Inflation erodes the real value of debt, which theoretically favors investing. However, if inflation leads to higher interest rates at renewal, the risk of increased debt servicing costs may outweigh investment gains.
Download our technical frameworks to compare lump-sum payments against portfolio growth over a 25-year horizon.