No. As often happens during the writer’s long process of creation, coincidences occur, disparate pieces link together to suggest commonalities. I’ve heard it said that there are no accidents. But often I discover only after a book is published (and a reader points it out) a symmetry I had not intended.
Although I’d been working on COME ON, RAIN! when a question from Eileen Christelow set me to thinking about the dustbowl, I didn’t intend to create a study of opposites with the two books. I simply followed the path of one book to the other and then back again.
The interpretation, the connection making, is often best left to readers who frequently discover parallels the writer never realized she/he was creating.