For a bivariate binary response model y, = 1 (xj βj+j 0), j=1,2, we propose to estimate nonpararnetrically the quadrant correlation E{sgn(u1) *sgn(u2)} between the two error terms ul and u2 without specifjing the error term distribution. The quadrant correlation accounts for the relationship...

Under a sample selection or non-response problem, where a response variable y is observed only when a condition δ = 1 is met, the identified mean E(y&7Cδ = 1) is not equal to the desired mean E(y). But the monotonicity condition E(y&7Cδ = 1) ≤ E(y&7Cδ =  0) yields an informative...