Will I be penalised if my economics job market paper is coauthored with my supervisor?
Economics is not my field, so my answer is based on what I've heard from other people. Generally, it is preferable if the job market paper has a sole authorship or at least if it is co-authored by other graduate students. However, I have heard of people getting jobs even with a job market paper coauthored with their advisor. Since you have two other papers, and one with sole authorship, that will to some extent work towards eliminating any negative impression that the job market paper may create. However, ultimately it will depend on your potential employers and the practices that they follow. Keep your fingers crossed and hope for the best.