Relating interest charges to economic growth

They are trying to figure it out. 

Conclusion

We do not have a definitive measure of how interest rates affect economic activity and inflation. However, along with other recent research, we find that interest rates have stronger effects on the macroeconomy than previously understood.

Interest charges cause us to skip long queues and select short ones; via the basket effect. Thus the dual supply and demand queues stay within some bound range and the virtual currency denominations  used for pricing all have the same  imprecision.

Economist get confused when they add time to the equation.