Compute land footprints by physical trade balance.

Estimate consumption-based land footprints by propagating direct land use through the bilateral physical trade network, an approach independent of the Leontief inverse used by compute_footprint(). Each country's supply pool (production plus imports) carries an embodied-land intensity s; solving the balance \((D - M) s = L\) per item gives s, where D is diagonal supply throughput, M routes import intensities, and L is direct land. The footprint of consumption (supply minus exports) is then consumption * s.

Unlike the multi-regional input-output method, this tracer handles only the trade dimension, not inter-product processing transformations. Comparing the two with compare_footprint_methods() isolates the effect of that assumption – an apples-to-apples stress test on shared FAOSTAT data.

Usage

compute_footprint_balance(production, trade, extension)

Arguments

production

Tibble with area_code, item_cbs_code and value (quantity produced).

trade

Tibble with from_code, to_code, item_cbs_code and value (quantity exported from from_code to to_code).

extension

Tibble with area_code, item_cbs_code and value (direct land use of domestic production).

Value

A tibble with area_code (consuming country), item_cbs_code, value (embodied land in consumption) and method ("land_balance").

Examples

production <- tibble::tibble(
  area_code = c(1L, 2L),
  item_cbs_code = c(10L, 10L),
  value = c(100, 0)
)
trade <- tibble::tibble(
  from_code = 1L, to_code = 2L, item_cbs_code = 10L, value = 40
)
extension <- tibble::tibble(
  area_code = c(1L, 2L),
  item_cbs_code = c(10L, 10L),
  value = c(50, 0)
)
compute_footprint_balance(production, trade, extension)
#> # A tibble: 2 × 4
#>   area_code item_cbs_code value method      
#>       <int>         <int> <dbl> <chr>       
#> 1         1            10    30 land_balance
#> 2         2            10    20 land_balance