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ECA’s multi-source approach to providing accurate cost of living indices

In last week’s blog post we looked at the various stages involved in calculating ECA’s cost of living indices. The first stage is to collect over 450 000 prices from all over the world every survey. Unsurprisingly, we are often asked how we collect this price data, so in this post we are going to take a closer look at how we source the information that feeds into the cost of living indices and other global mobility data we provide.

We use three sources to collect price data: ECA’s team of International Data Researchers (IDRs), field research companies and expatriates working for client companies. This enables us to cross reference for consistency and check for bias. It also allows us to gather a wide range of coverage and larger sample sizes to ensure greater statistical reliability.


Our team of researchers spend most of their time travelling around the world collecting prices for food and drink, household items, services, transport, accommodation and more. Not only do they bring back prices from the locations they visit but also updates regarding new developments and changes to shops, restaurants and venues which may have moved, closed or recently opened. This not only helps to inform our price collection process but also feeds into other ECA research such as our Country Profiles which help expats prepare for their assignment.

Field Researchers

Working with networks of data collection organisations enables ECA to extend the breadth and depth of its data even further. We ensure agents are well-briefed in exactly the items and outlets we wish to price based on the information we receive from expatriates and IDRs who have experience there. Our experienced team of cost of living analysts vigorously check for any irregularities in the data returned.


When we run our cost of living surveys we ask companies to invite their expatriates to get involved. By inviting them to record the prices of items in the outlets they regularly go to we not only get a true picture of where and how they shop, but give them an opportunity to have some involvement in how their cost of living allowances are calculated. The questionnaires received from assignees are subjected to a thorough verification process, where prices are checked against previous years’ and against each other to ensure validity and to pick up any anomalies or collusion between assignees. 

What this means for you

ECA’s multi-source approach guarantees integrity. The user can be sure of valid and representative data. Completed cost of living survey questionnaires from all our sources are collated and analysed using techniques that have been developed over the 45 years that we have been surveying living costs to publish consistent and defensible cost of living indices.
However, providing an index is just part of the story. Without knowing how and when to apply them, what to include or exclude in an index, how to calculate the spendable income to apply them to and how to update them, they are just a figure. Luckily, we have the calculators, software and knowledge to help you with that! 


ECA publishes cost of living data for more than 460 cities around the world. It is available from ECA in several forms: as part of a subscription in a calculator which allows you to experiment with different types of index and review the outputs; in reports, providing background detail for specific indices; and as part of the Build-up Calculator for performing balance-sheet remuneration calculations. Cost of living data is also pre-populated in ECAEnterprise, our Assignment Management System, and in our Net-to-Net Calculator.

  Please contact us to speak to a member of our team directly.


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