Compute the national cropland destiny mix over time

Computes, per year, the share of Spain's cropland output (by mass N) going to each destiny — domestic food, feed, exported food, non-food — from create_n_nat_destiny()'s national commodity balance sheets. Deliberately not create_n_prov_destiny()'s provincial data summed up: the provincial "export" destiny does not distinguish inter-provincial trade from true international export (per decompose_crop_livestock_conn()'s same caveat on "Outside" imports), which would overstate the export share here. create_n_nat_destiny() instead recomputes export/import directly from the national production-vs-consumption balance per item, so trade between two Spanish provinces nets out rather than counting as export. This is the supplementary diagnostic recommended in the decomposition proposal (section 14, "attach to existing figures"), to show the local-food -> feed + export transition directly, since decompose_cropland_surplus() no longer carries a destiny factor.

Usage

decompose_destiny_mix(n_nat_destiny = NULL, example = FALSE)

Arguments

n_nat_destiny

National nitrogen flows tibble from create_n_nat_destiny(). If NULL, computed automatically (slow).

example

If TRUE, return a small hardcoded output without downloading remote data. Default is FALSE.

Value

A tibble with columns year, destiny_grp (one of "domestic_food", "feed", "exported", "non_food"), output_mg, and share (that destiny's share of the year's total cropland output).

Examples

decompose_destiny_mix(example = TRUE)
#> # A tibble: 8 × 4
#>    year destiny_grp   output_mg  share
#>   <dbl> <chr>             <dbl>  <dbl>
#> 1  1960 exported         54087. 0.155 
#> 2  1960 feed            188775  0.540 
#> 3  1960 domestic_food   101884  0.292 
#> 4  1960 non_food          4554. 0.013 
#> 5  2000 feed            426311  0.556 
#> 6  2000 domestic_food   119629  0.156 
#> 7  2000 exported        205771  0.269 
#> 8  2000 non_food         14476. 0.0189