Cost-of-Living vs Cost-of-Labour: Why the Distinction Changes Your Pay Strategy

The Core Design Challenge

Cost of living measures what it costs for a person to maintain a specific standard of living in a given location. Indices like Mercer's Cost of Living survey or ECA International's data calculate how much a basket of goods and services costs in a given city relative to a base location. These measures are designed to answer a specific question: how much more money does someone need to maintain the same purchasing power in city A versus city B? This is exactly the right question for designing expatriate allowances — where the goal is to hold the employee financially harmless against the cost difference between their home and host location.

Cost of labour measures something entirely different: what employers in a given market must pay to attract and retain specific skills. Labour market prices are set by supply and demand — how many software engineers are available in Lagos relative to how many companies are competing for them. This is the correct input for setting pay for locally hired employees. It is determined by salary survey data specific to the relevant market, not by cost-of-living indices.

The two measures are correlated — higher-cost cities tend to have higher wages — but they are not identical, and the divergence can be significant. Software engineering skills in Lagos command market rates set by the intense competition between local fintech companies, international tech giants with African offices, and remote-first startups that recruit globally. The cost-of-living index for Lagos, relative to London, might suggest that Lagos engineers should be paid 30-35% of London rates. The actual labour market data for senior software engineers in Lagos will typically show rates that are substantially higher than a cost-of-living adjustment would imply, because the supply-demand dynamics for this skill are increasingly global.

How the Approach Works

The practical implication for Total Rewards professionals is straightforward: if you are setting pay for locally hired employees in a new market, use salary survey data from that market. If you are designing allowances for employees relocating from one country to another, use cost-of-living data. Do not swap these inputs. Using cost-of-living data to set local hire pay will systematically underprice skills in markets where labour competition is stronger than cost indices suggest — and overprice them in markets where labour competition is weaker.

High-inflation markets add a further complexity. When a market experiences 25-30% annual inflation — as Nigeria did in 2023-24 — the cost-of-living and cost-of-labour questions both become more urgent, but they remain distinct. An employee whose NGN salary has not been reviewed in 12 months has experienced a real-terms pay cut of 20%+ even though their nominal payslip shows the same number. The response to this is not to renegotiate their cost-of-living adjustment (unless they are an expatriate on an assignment package) — it is to review their salary against the current local labour market, which has likely repriced upward in NGN terms to reflect the same inflationary pressures. Keeping these questions conceptually separate is what allows the right answer to each of them to emerge clearly.