This isn't right. It could in fact mean prices are going down.
Had we just reported a month on month -0.4% instead of 0.4%, the yoy rate would have been reported as 6.9%. A headline of 6.9% would mean prices are actually going down.
Had we just reported a month on month -0.4% instead of 0.4%, the yoy rate would have been reported as 6.9%. A headline of 6.9% would mean prices are actually going down.
The discussion is around how the numbers should be interpreted. There isn't confusion around what they have literally reported.
The instantaneous slope would be negative if the last month happened to observe a slight decrease, true. But the slope of the line between last year and this year would be positive.
Both statements can be true:
1. prices just fell slightly since last month
2. prices have risen overall since last year
EDIT: you edited your comment I’m not going to update mine.
>> The instantaneous slope would be negative if the last month happened to observe a slight decrease, true
This is sloppy. It's fine, it's a forum, we aren't writing academic papers.
Nobody is trying to figure the slope of the straight line between the two points, that's what is already reported.
Yes, both can be true.
IDK… nobody is really trying to figure out how to interpret the data. People were just commenting that “declines to X%” actually still means that it’s gone up YoY and not that it’s declining YoY and here you are yelling that actually it is declining because recently it went down. Which is false, YoY.
They just take the recent point and the point from a year ago and do the math and report the change. For mom they do the recent point and the one before that, do the math and report.
Some people actually know what the CPI is, how it gets reported, and understand the shortcomings of said reporting. If you aren't one of those people, it's silly to go around correcting others.