About half comes from taxes on commercial activities and services within the areas IS controls (which include 7m people), 43 percent from oil revenue and the rest from drug smuggling, selling electricity and donations.
IHS notes tax revenues are hard to target but that the US-led coalition’s airstrikes have significantly degraded the group’s oil refining capacity and ability to transport oil via tanker convoys. Total oil production has reportedly fallen from 100,000 barrels a day to below 40,000.
IS’s defeat by Kurdish forces at Tal Abyad on the Syrian-Turkish border in June, and Turkey’s efforts to stop smuggling, have also forced it to rely increasingly on internal markets in Syria and Iraq to smuggle and sell oil.
IHS sees signs the group is struggling to balance its budget, including cuts to fighters’ salaries, price hikes on electricity and other basic services, and the introduction of new taxes.
The Islamic State caliphate is losing its appeal.