Price competitiveness of the dirham

Effective exchange rate: an average of the dirham against all its trading partners, weighted by each partner's share of Morocco's trade. The euro carries a lot of weight (Europe is the top partner), the yen very little — it's a global view, not the rate against a single currency.
Nominal exchange rate: the raw rate, as displayed by banks.
Real exchange rate: the nominal rate adjusted for relative inflation. If prices rise more slowly in Morocco than among its partners, Moroccan products become relatively cheaper, even without any movement in the displayed rate.

Concrete example (June 2026). The dirham is 16% higher than in 2020 in nominal terms, but 2.5% lower in real terms: stronger inflation among partners has erased the nominal appreciation. That's the entire gap between the two curves.

Practical reading. When the real index falls, Moroccan products gain price competitiveness for exports (favorable to exporters). When it rises, they lose it. Watch out for the counter-intuitive part: “the dirham is depreciating” sounds negative, but it is favorable to export competitiveness.
Both sides of the coin: a weak dirham helps exporters but makes imports (energy bill) more expensive. It is not unambiguously “good” or “bad”.

What is a base? The index equals 100 in the reference year. A country at 95 has gained 5% in price competitiveness since that date; at 110, it has lost 10%. Absolute competitiveness levels are not comparable across countries — Morocco at 97 and Turkey at 60 does not mean Turkey is “cheaper”. It only means Turkey has depreciated more in real terms since the base date. What's being compared are trajectories: a country whose curve falls gains price competitiveness for exports; a country whose curve rises loses it.

Why the BIS uses 2020. It's an institutional convention: the same base year for all 64 economies, which guarantees the comparability of published indices. But 2020 is also the year of Covid — collapsed tourism, exchange-rate shocks, erratic inflation. Comparing “since 2020” can therefore mainly reflect the exit from crisis, not an underlying trend.

Hence the base selector. Changing the base changes the question being asked. 2020 (BIS) = the official published index, which absorbed the Covid shock best. 2015 = medium term, excluding the shock. 2010 = long-run structural trend. Start of series = trajectory since the first date common to all displayed countries.
Note: only the 2020 base matches the official index published by the BIS. Other bases are recalculated in-house from the same BIS data.
BIS coverage: 9 countries displayed. Not available: Tunisia, Egypt (not in the BIS Broad basket). Source: BIS, same methodology for all countries.