It is no secret that states with empty container deposit systems result in higher return rates and less issue with roadside littering than states without bottle bills, but is that incentive diminishing over time with inflation? Case in point is an article in Slate (A Nickel Isn't Worth a Cent) which looks at the ever decreasing value of container deposits in the face of inflation. Author Daniel Engber notes that "In the time since deposits were invented, their value has declined by 83 percent: Today's nickel wasn't worth a penny in 1971."
Engber further suggests, quite reasonably, that the higher the deposit, the more effective it will be. He notes a return rate of 61 - 90 percent in bottle bill states, all of which carry a nickel deposit. The one exception is Michigan, which boasts a 95 percent return rate in conjunction with its 10 cent deposit.
The challenge is to shape behavior, and then maintain it. Shaping behavior typically implies more frequent or greater reinforcement, and then a reduced amount for behavior maintenance. I live in British Columbia. It seems here that most people are just conditioned to return bottles and cans to the depot, even though the deposit return amount is extremely nominal. With the actual value of the deposit decreasing over time due to inflation, bottle deposits still have been very effective. Having said that, it seems like a no brainer that if the deposit kept pace with inflation, then the return rate would be higher, generating more aluminum, glass and plastic for recyclers in the process.