Economic modelling is always research, subject to debate and continuous improvement. But at some point the powers that be need to do some real policy-making, taking decisions affecting lots of people. It can be informative to look at the tooling the said powers use to make their decisions more rational and data-informed. I haven't found before anything as self contained and fully disclosed as this project from the Danish Ministry of Finance, [DREAM-DK/MAKRO]( The stated goal is to understand, control or predict the economic results of shocks or interventions. Two strands of thought, equlibrium/dynamics and matrix modeling have neon signs for categorists saying "enter here". (ch. 10 of Documentation.pdf is dedicated to I/O tables). I have wanted to add this to this old, 2018 [post](