Bank reserves are a throwback to a time when the amount of receipts for money (gold) that could be issued by a bank was limited by the amount of money (gold) the bank held in reserve. Under the current monetary system bank reserves have no real meaning, since it isn’t possible for a dollar in a bank deposit to be genuinely backed by a dollar held somewhere else. The dollar can’t back itself! However, it is still important to understand what today’s bank reserves are/aren’t and how changes in the reserves quantity are linked to changes in the economy-wide money supply. Remarkably, these bank-reserve basics are misunderstood by almost everyone who comments on the topic.
The simplest way for me to deal with the common misunderstandings about bank reserves is in point form, so that’s how I’ll do it. Here goes: