This paper investigates the trade and economy-wide effects of the East African Community’s (EAC) 2022 enlargement, which
formally admitted the Democratic Republic of Congo (DRC) and South Sudan. Using a multi-region computable general equilibrium
model calibrated to the latest Social Accounting Matrices (2021–2023) and disaggregated by 28 tradable sectors and four primary
factors, we quantify the short- to medium-run impacts on GDP, welfare, trade flows, fiscal revenues and poverty. Scenario results
indicate that full implementation of the EAC customs union and common market rules would raise intra-EAC merchandise trade by
8.4 % (≈ US$1.0 billion) within five years, with Kenya, Uganda and Tanzania capturing the largest shares of new exports. The DRC
experiences the sharpest relative gains: real GDP is 2.1 % higher and household real incomes rise 1.6 % on average, driven by
improved market access for copper-cobalt value chains and reduced non-tariff barriers (NTBs) that lower trade costs by 6–9 %.
South Sudan’s welfare improves modestly (+0.7 %), mainly via cheaper imports and investment-goods inflows; however, fiscal
revenues contract by 3.2 % due to tariff elimination and limited domestic tax capacity. Community-wide, the enlargement raises
aggregate real GDP by 0.4 % and lifts an estimated 1.8 million people out of extreme poverty, two-thirds of whom reside in the DRC.
Sensitivity analysis shows that gains double when NTBs are halved and triple when accompanied by trade-facilitation improvements.

Conversely, delays in harmonising standards or persistent conflict in eastern DRC erode up to 60 % of the projected benefits. The
findings underscore the importance of complementary reforms—especially infrastructure upgrades, customs modernisation and
peace-building—to ensure that enlargement translates into inclusive and resilient growth.