These expectations are akin to asking “how much would my effective purchasing power go up if I buy JGBs?” They also can be viewed as equivalent to borrowers’ expectations regarding their real costs of borrowing, taking into account price changes, when they borrow money at a certain nominal interest rate.
Consequently, the lower the expected real rates, the more subdued their real cost of borrowing. The decline in expected real rates will stimulate demand in economic activity in a number of ways.