1. Overview — Our Approach
Institutional sources · Consistent baseline · Transparent estimates
The GlobalCostData index system answers a single practical question: compared to New York City, how expensive is it to live here? NYC is set to 100. A country scoring 48 costs approximately half as much; a country scoring 130 costs about 30% more.
We compute five sub-indices for each country — Cost of Living, Rent, Groceries, Restaurants, and Local Purchasing Power — then combine them into a single composite CoL Index using fixed weights. These weights reflect the typical monthly expenditure structure of a single expatriate adult living in an urban setting.
| Sub-Index | Weight in CoL Index | Primary Source |
|---|---|---|
| Cost of Living (ex-rent) | 30% | World Bank ICP |
| Rent Index | 30% | World Bank / city_prices DB |
| Groceries Index | 15% | World Bank ICP, Eurostat |
| Restaurant Index | 15% | city_prices DB, ILO |
| Local Purchasing Power | 10% | World Bank GNI PPP, ILO salaries |
2. The NYC Baseline
Why NYC = 100, and what that means in dollars
New York City (Manhattan + broader metro, USA) serves as the reference point for all indices. We chose NYC because it is one of the most thoroughly documented urban economies in the world, with deep, liquid markets for both rental housing and consumer goods that produce stable, verifiable price signals.
The four anchor values that define the NYC baseline are set annually and reviewed each January:
| Metric | NYC Baseline Value | Index Value | Notes |
|---|---|---|---|
| 1-bed rent, city centre | $3,200/month | 100 | Manhattan + close boroughs avg. |
| Meal, inexpensive restaurant | $20 | 100 | Per person, sit-down lunch |
| Monthly groceries (single) | $420 | 100 | Standard basket, supermarket |
| Monthly public transport | $132 | 100 | MTA unlimited monthly MetroCard |
These baseline values are held constant within each data year and updated in January using publicly published NYC market data. When a country's rent_1br_center is $640/month, its Rent Index is computed as (640 / 3200) × 100 = 20.
Practical reading
A country with CoL Index 45 costs roughly $1,440/month for the same lifestyle that costs $3,200/month in New York. A CoL Index of 110 means it is 10% more expensive than NYC — common for cities like Zurich or Singapore.
3. Primary Data Sources
Institutional, open, documented
All primary data comes from institutional sources with published methodologies and defined update schedules. We do not use consumer review platforms or self-reported surveys as primary inputs.
| Source | Data Type | Coverage | Cycle |
|---|---|---|---|
| World Bank Open Data data.worldbank.org |
GNI per capita (PPP), GDP, International Comparison Programme (ICP) price levels, inflation (CPI), poverty headcount | 198 countries | Annual (ICP 3–5yr cycle) |
| ILO — International Labour Organization ilostat.ilo.org |
Average net monthly salary (USD), labour force participation, wage growth | 180+ countries | Annual |
| Eurostat ec.europa.eu/eurostat |
Purchasing power parities, HICP (harmonised inflation), household expenditure structure | EU-27 + EEA | Annual / quarterly |
| UNDP — Human Development Reports hdr.undp.org |
Human Development Index (HDI), education index, life expectancy index | 191+ countries | Annual |
| WHO — Global Health Observatory who.int/data/gho |
Health expenditure per capita, physicians per 1,000 population, life expectancy | 194 countries | Annual |
| GeoNames geonames.org |
City and country reference data, population, geographic identifiers | Global | Continuous |
| GlobalCostData city_prices DB | City-level rent (1BR centre/suburbs, 3BR), meal prices, monthly transport, avg net salary — 3,413 data points across 3,400+ cities | 3,413 points | Monthly rolling |
4. Estimated vs. Real Data
What the ~ badge means
Not every data point for every country has a directly measured institutional value. When primary source data is unavailable for a specific metric, we derive an estimated value rather than leaving the field blank or using a placeholder.
Estimated values are produced by regression models calibrated on confirmed data from countries with comparable GNI per capita, regional membership, and price level indices. The model error for rent estimation is typically ±12%; for meal prices ±9%.
Wherever an estimated value is displayed, it is marked with a tilde: ~$640. Direct measurements from institutional datasets carry no tilde.
| Data Type | Badge | Source | Precision |
|---|---|---|---|
| Directly measured | no badge | World Bank, ILO, Eurostat, WHO, UNDP | High — institutional |
| Estimated / derived | ~ | GlobalCostData regression model | Medium — ±9–12% |
Currently, 191 of 198 countries have directly measured GNI per capita from World Bank. All 198 countries carry an expat value score. City-level rent data (directly measured) covers 2,224 of our 3,413 city price data points.
5. Update Frequency
When and how data is refreshed
| Data Layer | Frequency | Trigger |
|---|---|---|
| Country CoL indices | Monthly review | Manual QA + automated source diff |
| World Bank data ingestion | Annual (Q1–Q2) | World Bank annual release |
| ILO salary data | Annual | ILO annual ILOSTAT release |
| Eurostat PPP | Annual / quarterly | Eurostat publication calendar |
| City price points (city_prices) | Rolling monthly | New verified data points added continuously |
| NYC baseline anchors | Annual (January) | NYC published housing and transport data |
| Expat value scores | Quarterly | Source index updates |
Each country page displays the data vintage in the page metadata. The dateModified in each page's Schema.org markup reflects the most recent data verification date.
6. Methodology FAQ
Common questions about our data