The value of pennies to the economy must be much greater than $69M right? My reasoning is: if you get rid of them, who’ll get short changed? The consumer. And by how much throughout the entire cash economy? A lot.
I think the value of pennies to the economy is negative.
Every time I have to handle a penny it wastes my time and energy for no gain. I never find having a penny useful unless it will prevent me from getting more pennies. Multiply that by everyone in the country and that is quite a waste of time (i.e. money). There would be almost no loss of economic efficiency if we get rid of pennies but a nice savings in real time and energy, to say nothing of the waste that mining, refining, stamping and distributing them costs.
Why don't you just do what I do: when you buy something in-person with cash and there's change, count the paper money and then just hastily count out the change, knowingly giving more then the exact cent amount, and say "Keep the change, and no need for the receipt." Precious seconds can be saved every time. Also, if I'm in line behind someone who is taking too long with anything up to 2 dollars, I just say "I'll pay it" or I even quickly hand the cashier the money.
Why do you assume the consumer will always be short changed? Just use mathematical rounding which is fair. It's hard for merchants to price items so that the total ends up rounding upwards if you buy multiple items. People already subcontiously read 99c as $1 and will apply that thought even more if they know rounding will happen so it's not exactly like you are being cheated. For larger purchases even more so, would you consider $99, $99.99 or $100 different prices? No, the difference is irrelevant since the competitor across the street sells the same item for $89.
Even if you were being short changed at every purchase, assume 10c being the smallest coin available, you loose worst case 9c per transaction, assume you make 2 transactions per day. That's total $5.4 lost per month, I can live with that. Especially since it's a worse case scenario, realistically it's +/-0 and even if merchants have a special secret method for winning they can probably only win 5c on average making the loss half of my worst case scenario.