Coin collectors have been talking about this for years both the penny & nickel cost more than their value to mint. Another issue is the dollar coin (yes they exist.) The cost of dollar coins is a lot cheaper and will last much longer than a paper (actually cloth) dollar, but the company that supplies the US Mint with the "rag" (the companies term for the cloth) for paper money has bought and paid for enough congresspeople to insure that the coins are stored away and dollar bills are in circulation. There are warehouses full of dollar coins, you can get them at the bank but expect to wait as they retrieve them from the vault. All of this has been researched and reported to the Mint by their advisory committees, but Congress is getting paid too well to actually change anything. In addition to the copper and nickel lobbies, the coin operators lobby is also against it as they would need to alter the machines to not accept nickels or to accept a different weight coin plus be forced to accept dollar coins, as most machines will not take anything other than nickel, dime, quarter & bills.