A change in the depreciation rate would be one of the best ways to bring in new aircraft.
Not only would operators be more inclinded to invest in newer and safer aircraft, non-aviation people with $$ to spare would be tempted to invest and put aircraft 'on-line'.
Another advantage in the USA is that banks are a lot more mature when it comes to financing aircraft.
10-20 year terms are not unheard of in the USA.