ff_se_prod: Standard error for the product of two estimates

In forsythfuture/FFtools: Consolidates common functions and commands used by Forsyth Futures

Standard error for the product of two estimates

Description

This function calculates the standard error for the product of two estimates. An example is if users want to derive the number of people working by multiplying the total population by the percentage of the population that is working.

Usage

ff_se_prod(estimate_first, se_first, estimate_second, se_second)

Arguments

estimate_first	Point estimate of the first value.
se_first	Standard error for the first estimate.
estimate_second	Point estimate of the second value.
se_second	Standard error for the second estimate

Details

Reference for calculations: US Census Bureau, A Compass for Understanding and Using ACS Data, October 2008, A-16

Value

The standard error of the derived products.

Examples

df <- data.frame(pop = rnorm(n = 10, mean = 100000, sd = 20000),
                se_pop = rnorm(n = 10, mean = 1000, sd = 200),
                perc_working = runif(n = 10, min = .6, max = .9),
                perc_working_se = runif(n = 10, min = .05, max = .2))

# calculate standard errors of the products for each observation
ff_se_ratio(df$pop, df$se_pop,
           df$perc_working, df$perc_working_se)

# add columns to dataframe showing products and standard errors of products
dplyr::mutate(df,
              total_working = pop / perc_working,
              se_total_working = ff_se_prod(pop, se_pop,
                                            perc_working, perc_working_se))

forsythfuture/FFtools documentation built on April 5, 2022, 10:02 p.m.