Macroeconomics 5th Edition by Olivier Blanchard

Exercise 9

Bank runs and the money multiplier preferring to hold on to their cash.
During the Great Depression, the U.S. economy experienced many bank runs, to the point where people became unwilling to keep their money in banks, preferring to hold on to their cash cash.
How would you expect such a shift away from checkable deposits toward currency to affect the size of the money multiplier