Methodology
How we calculate the export concentration index, how to read it, and what it cannot tell you.
What the HHI measures
The Herfindahl-Hirschman Index (HHI) measures how concentrated exports are across trading partners. It is the sum of each partner’s squared share of exports: HHI = Σ si2, where si is partner i’s share of exports for a given geography, product category and month.
The HHI runs from 0 to 1. A value of 1 means a single partner takes all exports; a value near 0 means exports are spread evenly across many partners. Its inverse, 1 / HHI, gives the number of equal-sized partners that would produce the same concentration. An HHI of 0.50, for example, is what two equal-sized partners would produce.
Why a monthly index
Statistics Canada publishes export market concentration for Canada and the provinces, but only annually and without a product breakdown. We apply the same measure to monthly trade data, for Canada and each province, by product category and with or without the United States. The index is updated with each Statistics Canada trade release, not once a year.
How to read the levels
We classify each reading as low (below 0.15), moderate (0.15 to 0.25) or high (above 0.25). The trend chart marks 0.15 and 0.25 with coloured lines, and the comparison table colours each bar by its level.
Why the dashboard leads with the 12-month average
Monthly trade data is volatile. A single large shipment, a seasonal pattern or a swing in commodity prices can move one month’s HHI sharply. The dashboard therefore leads with the 12-month moving average, the mean of the latest 12 monthly values, and shows the monthly HHI as a dashed line on the trend chart. The cost is lag: a lasting shift shows up gradually in the average, half of it after six months and all of it after twelve.
Year-to-date figures
The comparison table also gives the year-to-date HHI, the average of the monthly HHI from January to the latest month, and compares it with the same months a year earlier. When a change is recent, the year-to-date figure picks it up sooner than the 12-month average.
Excluding the United States
The United States takes most of Canada’s exports, so it dominates the HHI. The “excluding the US” view drops the United States and recalculates each remaining partner’s share of non-US exports. It shows whether exports to the rest of the world are spreading across many markets or gathering in a few. The two measures can move in opposite directions. In July 2026, the 12-month average of the headline HHI fell to a record low while the average excluding the United States reached a record high.
Coverage
The dashboard covers Canada and the ten provinces from January 1997, across the product sections of the North American Product Classification System (NAPCS) that Statistics Canada uses for trade. The comparison table leaves out special transactions trade, a residual category whose movements carry little economic meaning.
Events on the chart
“Show events” marks three kinds of episodes on the trend chart: market shocks such as commodity cycles, financial crises and geopolitical events; trade agreements and infrastructure that opened new markets; and trade friction such as tariffs and import bans. Select an event to read what happened. The events give context. The HHI alone does not show that an event caused a change.
Source and revisions
The data come from Statistics Canada Table 12-10-0175-01, international merchandise trade by province, commodity and principal trading partners, in thousands of Canadian dollars. Each monthly refresh recalculates the full series from 1997, so the dashboard always reflects Statistics Canada’s latest revisions. The dataset is free to download under CC BY 4.0.
What the HHI does not tell you
The HHI measures concentration across destinations, not across products or producers. A province that sells one commodity to many countries reads as diversified.
It is calculated from export values, so commodity prices and exchange rates move it even when physical trade does not. For the same reason, a lower HHI is not proof of lasting diversification: a fall can reflect cyclical demand, prices or temporary disruptions.
Statistics Canada groups smaller markets under “Other countries”. The index treats this group as a single partner, which raises the HHI. The effect is largest for the view excluding the United States, where the group accounts for about 15% of exports.