Ludicracy/ludicrousness

In a profile, Philip Roth - I'm not sure whether this is a quote from his writing or something he said in an interview (though it strikes me as artfully balanced rather than spontaneous) - seems to distinguish between "ludicracy" and "ludicrousness":
"They made me very conscious of the difference between the private ludicracy of being a writer in America and the harsh ludicrousness of being a writer in eastern Europe." (Guardian.)
Why do you think he uses two different words? (He's surely too calculating a wordsmith to use an elegant variation for the sake of it.)

For some reason, I can't find "ludicracy" in any dictionaries, though Google produces many examples of its use. I'm wondering if it may be preferred, sometimes, because of a tinge of the word "lunacy".

I've never used it myself, perhaps because I sense it should be spelled "ludicrousy" in accordance with
jealous jealousy
or "ludicrosity" in accordance with
pompous pomposity
(I find no encouragement in
intimate intimacy
literate literacy
etc.)
Anyway, most words that end in "-ous" add the suffix "-ness" (seriousness, obviousness) or adapt to "-osity" (generosity, viscosity). Perhaps someone will enlighten me on the reason for the variation.
Peasemarch.