Of course economy is dinamic

 But like phisics if don't have the static that is inside the experiment isolate by the exterior facts the coeficients changed we don't have the original state, like a stoped body tends remains stoped, a body in moviment tends to remanis in moviment but the atrit stops it the gravity stops the ball of rise, in the space is diferent, have air, have gravity, have the atrit, have what powers influencing the moviment.

Rute Bezerra de Menezes Gondim