Indeed. And what will Erin do with that money? She will give it to Tony in exchange for some service. What will Tony do? Pay that into his bank account. Which

Indeed. And what will Erin do with that money? She will give it to Tony in exchange for some service. What will Tony do? Pay that into his bank account. Which means the bank now has an extra $70 (assuming they keep a $10 reserve) that it can loan out, bringing the total amount of money in our economy to $250. Also that $80 that Erin borrows will need to be paid back with interest. Say the interest is $20. She pays back $100. The bank now has $120. That $20 that she paid back had to come from somewhere. Say she sold a blanket she knitted to Paul to make that extra $20. Where did Paul get that money from? He had to borrow it from the bank. And the cycle continues...