This question concerns only USD, and doesn't need to be more granular than a year-level.
I am trying to create a model that takes various features into account in explaining why a particular service cost more in 2018 than, say, 2016. A monetarily small but important feature in this model would be accounting for how much of the increase in price was due to inflation.
On the surface this sounded very straightforward, from a base year use inflation data to calculate the value of a dollar in two target years and apply the difference as a multiplier. As I've delved into how how inflation is calculated and how to compute the relative value of a dollar, this has become more opaque.
My question is this: what is the most accurate way to calculate the difference in value of one dollar between two target years?