The question at hand is "how do we measure whether consumers have less purchasing power than before?"
It doesn't matter how long the BLS or yummyfajitas have been taking measurements. The only thing that matters is whether the measurement is accurately capturing what we want it to capture, and whether it shows that real ability to purchase stuff has gone up or down. The BLS measurement doesn't accurately measure purchasing power; it's misleading to act as though it does. A measure that takes the same items in 1980 and 2010 and compares wages to total price would be far better, and I contend that you would have to work very hard to create such a measure that shows what you claim.
My challenge to you: come up with the measure based on your actual spending habits. Compare your wage to that of someone in a comparable socioeconomic position 30 years ago, and calculate how much it would've cost to maintain an equivalent lifestyle 30 years ago. Unless you have very, very unusual spending habits, you'll find that your purchasing power is much higher now than someone in the same relative position in the 1980s.
It doesn't matter how long the BLS or yummyfajitas have been taking measurements. The only thing that matters is whether the measurement is accurately capturing what we want it to capture, and whether it shows that real ability to purchase stuff has gone up or down. The BLS measurement doesn't accurately measure purchasing power; it's misleading to act as though it does. A measure that takes the same items in 1980 and 2010 and compares wages to total price would be far better, and I contend that you would have to work very hard to create such a measure that shows what you claim.
My challenge to you: come up with the measure based on your actual spending habits. Compare your wage to that of someone in a comparable socioeconomic position 30 years ago, and calculate how much it would've cost to maintain an equivalent lifestyle 30 years ago. Unless you have very, very unusual spending habits, you'll find that your purchasing power is much higher now than someone in the same relative position in the 1980s.