A new approach to economic forecasting is under development. Existing economic forecasting methods produce a simulation error that is "unknown". This requires intervention by forecasters to process differences between model predictions and actual data from the recent past. Because the intervention process is specific to individual forecasters, two forecasters using the same model can end up with very different forecasts. The new approach, called Economy Dynamics, follows scientific methodology and by using engineering and data science analytical methods avoids unknown errors. This means the forecast is independent of the analyst running the simulation. This will enable forecasts to be validated against metrics at a regional level such as economic output, poverty levels and inflation and against the environmental impact of consumer behaviour, which is not currently possible.