How do you forecast demand for industrial machinery in emerging markets?

For Southeast Asia construction equipment, I'd start with a combo of top-down (GDP growth + construction spend as % of GDP from World Bank/ADB data) and bottom-up (unit sales from local trade associations like ICEMA in Indonesia or TEDA in Thailand). Cross-check with customs/import data from each country's trade ministry — it's messy but gold. Frost & Sullivan and Off-Highway Research have paid reports too if you have budget.