Q.71 An economist is utilizing the Gauss+ model to understand the evolution of interest rate factors over time. The model involves mean-reverting processes, where the expected change in the short-term factor is calculated. Given: the mean reversion speed parameter for the short-term factor $a_r = 0.6$, the medium-term rate $m_t = 0.027$, the current short-term rate $r_t = 0.02$, and the small time increment $dt = 0.01$, what is the expected short-term factor change?