CREATE TABLE authors (authid DECIMAL, lname TEXT, fname TEXT)
CREATE TABLE papers (paperid DECIMAL, title TEXT)
CREATE TABLE inst (instid DECIMAL, name TEXT, country TEXT)
CREATE TABLE authorship (authid DECIMAL, instid DECIMAL, paperid DECIMAL, authorder DECIMAL)

Find the country that the most papers are affiliated with.
SELECT t1.country FROM inst AS t1 JOIN authorship AS t2 ON t1.instid = t2.instid JOIN papers AS t3 ON t2.paperid = t3.paperid GROUP BY t1.country ORDER BY COUNT(*) DESC LIMIT 1
SELECT "t1"."country" FROM "inst" AS "t1" JOIN "authorship" AS "t2" ON "t1"."instid" = "t2"."instid" JOIN "papers" AS "t3" ON "t2"."paperid" = "t3"."paperid" GROUP BY "t1"."country" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1