nc_revenue: Calculate revenue for annual vs lifetime scenarios
In southwick-associates/lifetime: Provide functions for lifetime pricing

Description Usage Arguments Functions See Also Examples

Calculate revenue for annual vs lifetime scenarios

nc_annual_stream(retain_all, prices, wsfr_amount = NULL,
  min_amount = NULL, senior_price = NULL, senior_age = 65,
  age_cutoff = 80, youth_ages = 0:15)

nc_annual(retain_all, prices, wsfr_amount = NULL, min_amount = NULL,
  senior_price = NULL, senior_age = 65, age_cutoff = 80,
  youth_ages = 0:15)

nc_lifetime(prices, return_life, inflation, wsfr_amount = NULL,
  min_amount = NULL, perpetuity = TRUE, youth_ages = 0:15,
  age_cutoff = 80, fund_years = 0:50)

nc_lifetime_stream(prices, return_life, inflation, wsfr_amount = NULL,
  min_amount = NULL, fund_years = 0:500, youth_ages = 0:15,
  age_cutoff = 80)

`retain_all`	data frame of predicted years by age like that produced by `nc_retain_all`
`prices`	data frame of lifetime prices by age with at least 2 variables: current_age and price_lifetime
`wsfr_amount`	numeric estimated amount for aid dollars (use SFRF for fishing, WRF for hunting)
`min_amount`	numeric the minimum expenditure that will count for a certified hunter/angler (use 2 for hunt/fish and 4 for combo)
`senior_price`	numeric price for a senior lifetime license
`senior_age`	numeric age when a participant will be expected to buy a cheap lifetime license
`age_cutoff`	numeric final age that can be counted for lifetime license-based WSFR dollars
`youth_ages`	if not NULL, assumes for youths that the fund is able to compound until adulthood (when the agency will begin drawing revenue). See `nc_price_lifetime_youth` for details.
`return_life`	percentage return from lifetime fund
`inflation`	inflation rate for depreciation of lifetime fund
`perpetuity`	if TRUE, use a perpetuity calculation (https://en.wikipedia.org/wiki/Perpetuity) instead of `present_value`
`fund_years`	range of years to cast forward for stream-based lifetime fund valuation

nc_annual_stream: Stream of Revenue for annual scenario (Revenue|A)
nc_annual: Total Revenue for annual scenario (Revenue|A)

Convenience function to pull total revenue across all years
nc_lifetime: Revenue for lifetime scenario (Revenue|L)
nc_lifetime_stream: Stream of Revenue for lifetime scenario (Revenue|L)

Other wrapper functions for NC results: nc_break_even_yrs, nc_break_even, nc_price_lifetime_youth, nc_retain_youth, nc_retain

library(dplyr)
library(ggplot2)

data(retain_all)
data(retain)

# parameters
senior_price <- 15 # lifetime license price at age 65
wsfr_amount <- 16.65 # WSFR estimated aid amount per sportsman
min_amount <- 4 # WSFR minimum revenue for certified sportsman calculations
return_life <- 0.05 # annual return to lifetime fund
inflation <- 0.02 # inflation rate for fund depreciation
prices <- tibble(
    current_age = 0:63,
    price_lifetime = rep(250, 64),
    price_annual = rep(36, 64)
)

# total revenue
annual <- nc_annual(retain_all, prices, wsfr_amount, min_amount, senior_price)
ggplot(annual, aes(current_age, revenue_annual, fill = stream)) + geom_col()

lifetime <- nc_lifetime(prices, return_life, inflation, wsfr_amount, min_amount)
ggplot(lifetime, aes(current_age, revenue_lifetime, fill = stream)) + geom_col()

# revenue streams
nc_annual_stream(retain_all, prices, wsfr_amount, min_amount, senior_price) %>%
    filter(age_year >= 16)
nc_lifetime_stream(prices, return_life, inflation, wsfr_amount, min_amount)

# break-even
x <- nc_break_even(retain_all, prices, return_life, inflation, wsfr_amount,
                   min_amount, senior_price)
ggplot(x, aes(current_age, break_even)) + geom_line()

# years to break-even (using revenue stream calculations)
x <- nc_break_even_yrs(retain_all, prices, return_life, inflation, wsfr_amount,
                       min_amount, senior_price)
ggplot(x, aes(current_age, yrs_to_break_even)) + geom_col()