Before revision:  The unexpected fluctuations of the long-term real interest rate can be explained by existence of special type of cycle called relaxation oscillation on money (or financial assets) market. Relaxation oscillations include some short parts looking like "jumps". These "jumps" can be interpreted like unexpected. In other words, we try to explain these "unexpected" fluctuations of long-term real interest rate and show that these fluctuations can be only seemingly unexpected.
After revision:  The unexpected fluctuations of the long-term real interest rate can be explained . We describe a macroeconomic environment by the modification of the fundamental macroeconomic equilibrium model called the IS-LM model.