Pick of the Paperbacks; Jailbird, by Kurt Vonnegut. New York: Dell Publishing Co. $3.25.

A superb, zany satire, establishing Vonnegut as a modern-day Swift able to evoke a sting and a laugh with a single stroke. Vonnegut gives us prose that is lean, bitingly funny, and a pleasure to read. Its effect here is to cast a fairy-talish quality on 20th-century American politics as experienced by a bumbling Everyman. The author sees in recent Amercan events -- Watergate, the labor movement, big business run amuck -- an atmosphere as fantastic as anything the imagination could create. Life for his character, Starbuck, is little more than one absurd misadventure after another, mirrori ng the real- life events that are his backdrop.