Two of the four requested metrics can span 1975–2024; housing prices per m² and average salaries cannot, as defined

Feasibility of a 50-year cross-country housing, GDP, wage and migration panel — four requested metrics assessed against their strongest global long-run source, over the proposed window of 1975–2024, the last 50 complete calendar years (2025 is not uniformly complete).

source supports the 1975–2024 global panel source does not support it as requested historical start not established globally proposed analysis window 1975–2024

The critical gap is housing: the authoritative long-run global source is a residential property-price index, nominal and real, not an absolute €/US$/m² price — so a consistent all-country price-per-m² series cannot be calculated for 50 years. data.bis.org

GDP per capita is the strongest lane: the World Bank series starts in 1960 and supports a 50-year country-year panel, subject to country-level missing values — but per-capita vs total and constant-USD vs PPP must be fixed before joining. ourworldindata.org

"Average salary" has a rigorous counterpart — average annual full-time-equivalent wage per dependent employee — but coverage is OECD members and selected partners only, narrower in geography and history than GDP and migration; ILOSTAT is needed for broader coverage. oecd.org

"Migration amount" is operationalized as annual net migration — immigrants minus emigrants, citizens and noncitizens, in people per year — available from 1950 with estimates and country-level gaps; migrant stock or gross flows would answer a different question. statbase.org

Decisions needed before calculation

Country list — the request names none; every source has country-level gaps, so the list determines feasibility.
GDP variant — recommend real GDP per capita on a constant-price basis; confirm per capita vs total, and constant USD vs PPP.
Salary basis — recommend the real PPP annual full-time-equivalent wage; accept OECD-only geography or add ILOSTAT for breadth.
Migration concept — recommend annual net migration; state explicitly if migrant stock or gross inflows/outflows is wanted instead.
Housing — either accept the BIS house-price index for long-run analysis, or shorten the period to where absolute per-m² data exists.

Requested metric	What actually exists	Unit	Coverage	From	1975–2024 panel	Source
Residential price per m²	Quarterly residential property-price index; selected series is closest to nationwide coverage	Index (nominal and real), not an absolute currency price per m²	Around 60 economies; historical series back to around 1970 for 23 countries	1970	No	data.bis.org
GDP per capita	GDP per capita, World Bank series distributed by Our World in Data	Constant-price series for trends; exact currency/base year must be fixed before joining	Countries and aggregates in the World Bank series	1960	Yes, with country-level missing values	ourworldindata.org
Average salary	Average yearly wage per dependent employee in the total economy, full-time-equivalent (OECD)	Annual wage; currency/PPP presentation must be fixed	OECD members and selected partner/aggregate series, not every country	—	No	oecd.org
Migration amount	Net migration: immigrants minus emigrants, including citizens and noncitizens	People per year	Countries and world aggregates	1950	Yes, with estimates and country-level gaps	statbase.org

Feasibility and source matrix: 4 rows, one per requested metric, each pairing the request with its strongest global long-run source (definition, unit, earliest coverage, feasibility verdict, source URL). Feasibility is judged against a 1975–2024 all-country annual panel. Distinctions maintained: absolute price per m² vs house-price index; GDP per capita vs total GDP; net migration vs migrant stock or gross flows; annual full-time-equivalent wage vs informal average salary. Nothing was cut; all four rows are shown in full.