Complexity

If a recursive algorithm calls itself twice for each element in a set, does that mean it has n^2 complexity, or is that 2n and therefore n complexity? I am confused.

#lang racket
(define (all-pairs s)
    (if (<= (length s) 1) '()
        (append (map (λ(x)(cons (car s) x))
                     (cdr s))
                (all-pairs (cdr s)))))