There are no “tricks” here. Indeed, all of the tricks are used by our governments. The green line shows average wages, discounted by inflation calculated with the same methodology for all 40 years. Obviously that is the only way in which we can compare any data over time: through applying identical parameters to it each year.
Then we have the blue line: showing wage data discounted with our “official” inflation rate. The problem? The methodology used by our governments to calculate inflation in 1975 was different from the method they used in 1985, which was different than the method they used in 1995, which was different than the method they used in 2005.
Two obvious points flow from this observation. First, it is tautological that the only way in which data can be compared meaningfully is to use a consistent methodology. If the government thinks it has improved upon its inflation methodology, then all it had to do was take all of its old data and re-calculate it with their “improved” methodology. Since 1970 there is this invention called “computers” which makes such calculations rather simple.
This brings us to the second point: the refusal of our governments to adopt a consistent methodology in reporting inflation statistics can only imply a deliberate attempt to deceive, since it is 100% logically/statistically invalid to simply string together disconnected series of data — and present it as if it represents a consistent picture. More specifically, we can see precisely what lie our government was attempting to get us to believe.
I’m not so sure about the conspiracy theory, but this article does raise some interesting points, both about the validity of data analyses and growing poverty.