with the technological advancements that have occurred, would certain things--like a savings account--be reconsidered as M1? has the ease of access reached the point where it can be considered liquid-y enough? or are there strict definitions for liquidity?
Good question. Savings account are actually limited by whatever agreement you signed with your bank. For example, my savings account is less liquid than my checking because if my balance drops below $300 dollars at any point in the month, I get charged a fee. I would argue that you are correct in the general sense that checking accounts are more liquid than cash ever was.