nc_break_even: Find lifetime price (by current_age) where Revenue|A ==...
In southwick-associates/lifetime: Provide functions for lifetime pricing

Description Usage Arguments See Also Examples

This uses a solver function, uniroot, to find break-even prices for lifetime licenses.

nc_break_even(retain_all, prices, return_life, inflation,
  wsfr_amount = NULL, min_amount = NULL, senior_price = NULL,
  senior_age = 65, perpetuity = TRUE, youth_ages = 0:15,
  age_cutoff = 80, max_price = 1000)

`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
`return_life`	percentage return from lifetime fund
`inflation`	inflation rate for depreciation of lifetime fund
`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
`perpetuity`	if TRUE, use a perpetuity calculation (https://en.wikipedia.org/wiki/Perpetuity) instead of `present_value`
`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.
`age_cutoff`	numeric final age that can be counted for lifetime license-based WSFR dollars
`max_price`	Maximum lifetime license price used in solver function. A lower number will allow the function to execute more quickly.