Economics? That is true but there other reasons Japan could
not defeat the US. Japanese war strategy sucked in many ways. For
example often the US would rotate fighter pilots home so they could
help to train new pilots and provide up to date tactical information
Japanese pilots stayed in combat zone and perished with their
unshared experience.
The Japanese soldiers were mostly fanatical but stupid. My paratrooper
dad and his division pursued the Japanese thru the mountain Jungles
of Leyte. When the Japanese became hungry they would stop beside
a creek, start a fire, and boil rice. Of course the fire would mark their
position. Their leather belt and other gear would acquire a nasty odor
in the jungle humidity. This would also betray their position. The ways
that the Japanese lagged behind the Yanks are too numerous to tally.
Well, their tactical strategies like mass banzai charges certainly didn’t help matters. They largely abandoned these wasteful tactics by late 1944 and early 1945 and improved their defensive tactics at Iwo Jima and Okinawa but it was by then all for naught.