System economy is generated by calculating the weighted sum of the various station economies, then take the two largest components of that.
So you might have a lot of Agri/HT facilities, but if the Extraction/Industrial markets are bigger (simplistically, higher population), that will result in an Ext/Ind system display.
That doesn't matter in itself - system economy does absolutely nothing other than change the colour of your system on one galaxy map filter. It's the individual station economies which are important for things like mission generation, market export and import, and so on.
Many of your large station economies probably also have changed from previously, which will have had this effect. That may well matter, depending on what you're going for.
As far as why:
- Frontier released Update 3 on Wednesday
- having described the ground-up rewrite of economic behaviour in the advance patch notes
https://forums.frontier.co.uk/threads/elite-dangerous-trailblazers-update-3-now-live.636973/ last Friday (it's most likely the planetary influence rather than the weak links which are causing the shift in your aggregate system economy)
- which implements their earlier threat/aim to rewrite economic behaviour in that way from
https://forums.frontier.co.uk/threads/elite-dangerous-colonisation-facilities-markets.635519/ on March 21st
This change is good for:
- people who want their stations to produce something other than H-Fuel and Biowaste, but don't particularly care
what, especially those who either didn't read the documentation provided with the original behaviour or didn't have the baseline understanding of how economies work in Elite Dangerous to realise what it implied.
- people building systems with a small number of facilities
This change is bad for:
- people who weren't treating the Beta period as purely experimental [1]
- people building larger systems as economic producers, who want specific commodities to be available
[1] Frontier have
not said that the current economic behaviour is the final one; having shown willingness to make major backward-incompatible changes two months in, they could well make another. So now is not the time to start building up your "real" systems either.
).
