Your statement "...Over the past decade, the world has consistently faced an environment in which the propensity to save exceeded the propensity to invest, ..." certainly does not apply to the developed Western economies, which are drowning in debt due to overborrowing to buy overpriced assets, including housing and equities.
With historically low savings rates in the US, coupled with historically high debt-to-GDP ratios, debt-to-income ratios, etc, your notion that assets like housing are not in a bubble are not supported by facts. The thesis that rising asset prices are a sign of savings would be true only if the assets were being purchased with savings, not with debt.
What Housing Bubble? [View article]
With historically low savings rates in the US, coupled with historically high debt-to-GDP ratios, debt-to-income ratios, etc, your notion that assets like housing are not in a bubble are not supported by facts. The thesis that rising asset prices are a sign of savings would be true only if the assets were being purchased with savings, not with debt.