Download the bilateral mobility sources used to build the fused OD structure

Fetches the three external origin-destination sources that process_mobility_od_data fuses into a connectivity structure for est_mobility: UN DESA bilateral migrant stock, Abel & Cohen bilateral migration flows, and the Meta (Facebook) Social Connectedness Index. The fourth source, land contiguity, is derived locally from the ADM0 shapefiles and needs no download.

Usage

download_mobility_od_sources(
  PATHS,
  sources = c("desa", "abel_cohen", "sci"),
  snapshot_date = Sys.Date(),
  overwrite = FALSE,
  verbose = TRUE
)

Arguments

PATHS: List of paths from get_paths. Must include DATA_RAW.
sources: Which to fetch. Default all three.
snapshot_date: Date stamp for the archive subdirectory. Defaults to Sys.Date().
overwrite: If FALSE (default), an existing snapshot is kept.
verbose: Print progress.

Value

Invisibly, a data.frame: source, ok, bytes, file, note.

Details

All three are open; none needs credentials.

Sources and provenance

UN DESA International Migrant Stock 2024: Bilateral migrant stock (persons born in the origin residing in the destination), Table 1, 2024 both-sexes column. ~6 MB xlsx. The un.org host rejects a default libcurl agent with HTTP 403, so a browser User-Agent is sent. Licence: UN open data.
Abel & Cohen 2022: Bilateral migration flow estimates (Sci Data), figshare article 12845711, bilat_mig_sex.csv (~23 MB), ISO3 already. The da_min_closed estimator over the latest period is used downstream. Licence: CC BY.
Meta Social Connectedness Index: HDX social-connectedness-index, resource country.csv (~0.6 MB), columns user_country/friend_country (ISO2) and scaled_sci. Licence: CC BY-NC (Meta Data for Good) – see the note below.

Deviation from the E3 prototype. The original MOSAIC-OCV E3 work used the GADM-1 resource (273 MB) and summed sub-region pairs up to national totals. country.csv is Meta's own national-level product: ~500x smaller, no aggregation step, and a directly-measured national index rather than a sum of relative sub-national indices. Because the two are not guaranteed to be proportional, a fused structure built here is close to but not byte-identical with the E3 artifacts.

Licensing. Meta SCI is CC BY-NC. That is more restrictive than the other MOSAIC inputs and than the CC BY / UN terms of DESA and Abel-Cohen. Set sources to exclude "sci" (and reweight in process_mobility_od_data) if a downstream use is commercial.

Examples

if (FALSE) { # \dontrun{
PATHS <- get_paths()
download_mobility_od_sources(PATHS)
process_mobility_od_data(PATHS)
} # }