For a postscript copy of this paper, click here. This study reports on computational experiments for an agent-based labor market model with adaptive choice and refusal of worksite partners and with endogenously evolving worksite behaviors. Two treatment factors are experimentally varied: market structure; and ex ante capacity constraints on potential work offers and job openings. Particular attention is focused on experimentally determined correlations between treatment factors and the formation of contractual networks among workers and employers, and between contractual network formation and the types of worksite interactions and welfare outcomes that these contractual networks support.