Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

TelDat25 — Sat, 10 Apr 2021 23:53:51 GMT

Thanks.

It appears that the % change coincides with the way that a % change is usually calculated --> (X1 - X0)/X0

Will review the margin of error on % change formula.

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

Matthew Brault — Mon, 29 Mar 2021 17:27:04 GMT

I just plugged your numbers in:

55055 --> 79201

43.9% increase with a margin of error +/- 6.3%

The 90% confidence interval is 37.6% to 50.1%.

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

Matthew Brault — Mon, 29 Mar 2021 17:19:21 GMT

C = Current estimate, M_C = Margin of error on Current Estimate,

P = Previous estimate, M_P = Margin of error on Previous Estimate,

% change = (C-P) / P = (C/P) - 1

Margin of error on % change = sqrt( M_C^2 + (C/P)^2 * M_P^2 ) / P

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

TelDat25 — Fri, 26 Mar 2021 23:49:48 GMT

Thanks for the insight.

Did click the link and it appears to only address the various confidence intervals, at 90%, 95% and 99%.

For additional context, if the current and prior estimates pertain to estimates of average earnings for a particular zip code, current estimate from the ACS 5 Year 2019 Survey and prior estimate from the ACS 5 Year 2014 ACS Survey, I need to obtain the percentage increase (or decrease) between these two estimates.

But, the margin of errors are different.

Maybe the formula should incorporate the ratio of the margin of error to the estimate and then standardize this so that there is an "apples to apples" comparison between the estimates. Then, I can divide the adjusted current estimate by the adjusted prior estimate.

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

TelDat25 — Fri, 26 Mar 2021 23:35:46 GMT

Appreciate the insight.

Considering that each estimate, for the current period and for the prior period will have a standard of error computed by dividing the Margin of Error (MOE) by 1.645, but the formula displayed on page 8 of the pdf document below only display "SE."

SE(X/Y)

X being the current estimate and Y being the prior estimate. The percent change (X/Y) is reduced by multiplying by the standard of error. In essence, reducing the percent change by the standard error.

But, which standard of error calculation should be used? The one for the current estimate or the one for the prior estimate?

Instinctively, one would reasonably assume that both standard of estimates should be considered and maybe should be applied separately to each estimate first before calculating a percent change involving margin of errors.

Will try maybe, (SE_Current Estimate x Current Estimate) divided by (SE_Prior Estimate x Prior Estimate)

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

Douglas White — Fri, 26 Mar 2021 20:24:52 GMT

I cannot remember where I downloaded this excel program from, but it has a worksheet that will calculate percentages and their margin of error.

https://www.dropbox.com/s/n7x3ocj0pujgwn6/acs_statistics_calculator.xlsx?dl=0

RE: Percent Change Between two estimates from non-overlapping ACS 5 Year Surveys

Matthew Brault — Fri, 26 Mar 2021 20:23:42 GMT

Check out page 7-8 of:

https://www2.census.gov/programs-surveys/acs/tech_docs/accuracy/2019_ACS_Accuracy_Document_Worked_Examples.pdf