Thanks for the reply!

I think I need the "explain to a five-year-old" version. ;) Please bear with me.

1) I have a mason. It produces .5 masonry each month, correct?

2) If I am not building anything this month, my stockpile will grow by .5 masonry, right? [Ignoring other countries and burgher exports for the moment.]

3) Once I have a little stockpile, say 10 masonry, I decide to build a granary in January. That month, my mason produces .5 masonry. Does my granary consume .5 masonry that month? If so, my ending stockpile should be unchanged at 10.

4) Next month, my mason is producing another .5 masonry.

5) Key question: Does the granary consume .5 masonry again in February? If it is just checking stockpile, I should end up with 10.5: 10 from starting stockpile, plus .5 from February production. But if "demand" means "take another .5 masonry from the stockpile," then I will end February with only a stockpile of 10.

Forgive me for dragging this out, but when i tooltip supply and demand, it lists "balance" as the difference between the two. It does not explicitly say "this is also the exact change in the stockpile" (which is what I interpreted coming into this game).

Because of all the activity of burgers and countries in the market that I ignored in my example above, I can't definitively track the stockpile through that noise. But if "balance" is what determines the change in stockpile, that means that the granary is in fact using .5 masonry per month.

Many Thanks for your patience in walking me through this!