$(25$ points$)$ In a study of the influence of financial institutions on bond interest rates in

Germany, quarterly data over a period of $12$ years were analyzed. The postulated model

was

$y_i={}_0+{}_1{x}_{1i}+{}_2{x}_{2i}+{}_i$

where

$y_i=$ change over the quarter in the bond interest rates

$x_{1i}=$ change over the quarter in bond purchases by financial institutions

$x_{2i}=$ change over the quarter in bond sales by financial institutions

The estimated regression coefficients were as follows:

$b_1=0\mathrm{.}057,b_2=-0\mathrm{.}065$

Interpret these estimates.