Shamla Yoosoof, an investment researcher from Colombo, left Sri Lanka with her 3-year-old son and a jam-packed suitcase, swapping economic chaos at home for a new start in Dubai.

She flew out in June to join her husband who had secured a job as a sales and marketing director there weeks before — one of tens of thousands of Sri Lankan professionals escaping the country's worst economic crisis in seven decades.

Although the exact number of migrants was unavailable, both preliminary data and business leaders suggested the scale of the brain drain was serious enough to delay any economic recovery.