 The Klick/Stratman paper cited above found several effects of specific tort reforms on infant mortality that lost statistical significance when looked at more closely—that is, correlation with other state-specific factors wiped out apparent increases in mortality from joint and several liability reform but also wiped out apparent decreases in mortality from capping economic damages and restrictions on contingency fees.The only tort reform effect that proved robust was a negative effect of collateral source reform on black infant mortality.Proponents of tort reform counter by pointing to data from New Zealand, which has abolished its medical tort system but has medical error rates close to those in the United States.