Who should I believe, a government agency conducting a methodical survey of the country's economy, or some guy with a list of numbers that's possibly cherry picked?
But I don't because it literally takes an entire government agency to do it right. The incentives might be misaligned, but the BLS is a large enough entity that if there really were problems with their methodology, it would be publicized. Short of that, I'm more inclined to believe the BLS over a random commenter.
> But I don't because it literally takes an entire government agency to do it right.
It doesn't really. If you track your expenses consistently over the years (gnucash et.al.) you can trivially plot the increase in cost of living and the acceleration of that increase last handful of years.
That's fraught will all sorts of biases. What if your shopping habits changed? eg. you started becoming more health-conscious and started buying healthier (and more expensive) foods. The BLS accounts for all of that by measuring the price of a fixed basket of goods, which mitigates those effects. The same can't be said of your budgeting spreadsheet. Or maybe your area is undergoing gentrification and the discount supermarket got replaced with a whole foods. Your grocery spending might have went up 50%, but that doesn't mean it's a meaningful representation of what's happening across the country.
They're also anonymous, so you should assume the worst. This is especially true when the supporting evidence is suspect (ie. a bunch of arbitrary picked numbers). On the other hand the BLS's methodology is documented (https://www.bls.gov/opub/hom/cpi/), so I'm willing to give them a pass even though their incentives might be skewed.
>(what would it be?)
their beliefs? "agenda" here doesn't have to be something nefarious. an anti-vaxxer's agenda is anti-vaccine, but that doesn't mean they're scheming to get everyone infected.