This goes hand in hand with Americans delaying formation of families and fertility rates turning negative.
Admittedly, one part of the reason adoptions are down is because in 2012 Russia and Guatemala chose to temporarily halt adoptions to the U.S. and the standard of living in China has been improving. But that can’t explain all of the decrease.
Another minor contributory reason could be that white Christian America—the demographic most likely to adopt—hasn’t been doing so well in recent years.
This 2018 article says that U.S. international adoptions are down 81% (since 2004) and projected to completely end by 2022.
The reason the U.S. has adopted so many children from other parts of the world is because it has traditionally been a wealthy country.
What does it mean when international adoptions from other parts of the world completely come to an end?
Note: All these statistics are from a couple of years ago, so may not reflect on the economy over the last 2 years. I think it shows the depth of the Recession more than anything else.