Interesting proposition. There is a lot of possibly unnecessary packaging on many consumer products, especially items like cell phones, televisions, coffee makers, and the like.
The Amazon and eBay phenomena also greatly contribute to this waste. A packaging tax would certainly give manufacturers an incentive to reduce that packaging if applied at the producer end.
However, the point is well taken that this could then create an extra tax burden to shoppers at the grocery store as manufacturers pass the cost on to the consumer.
The pay-as-you-throw (a.k.a. SMART - save-money-and-reduce-trash) model also works to put the cost onto the “trashers,” and it is certainly easier to institute at the local level without the need for legislation.
But PAYT doesn't necessarily induce reduction on the part of the manufacturers.
Perhaps some combination is needed: a tax on non-recyclable packaging and PAYT for the municipal solid-waste stream.