Strong-Δ-Rationalizability introduces first-order belief restrictions in the analysis of forward
induction reasoning. Without actual restrictions, it coincides with Strong Rationalizability
(Battigalli, 2003, Battigalli and Siniscalchi, 2003). These solution concepts are based on the
notion of strong belief (Battigalli and Siniscalchi, 2002). The non-monotonicity of strong
belief implies that the predictions of Strong-Δ-Rationalizability can be inconsistent with
Strong Rationalizability. I show that Strong-Δ-Rationalizability refines Strong …