Econ Papers Daily / 期刊论文
律师的价值：担保来源规则变更作为无效工具
The Value of an Attorney: Collateral Source Rule Changes as an Invalid Instrument
摘要
The value of lawyers to their clients is notoriously difficult to estimate because of endogeneity. We utilize modifications to the collateral source (CS) rule that require reducing trial awards by the amount of payments from first‐party insurance as an instrument for hiring a lawyer. The problem with our instrument is that modifications to the CS rule have a direct effect on recovery and, hence, violate the exclusion restriction required for a valid instrument. We develop a new identification and estimation method that uses CS rule changes as an invalid instrument and bounds the impact of lawyers. We find that our estimated impact's upper and lower bounds are lower than estimates that do not correct for endogeneity. Our estimates of the impact of lawyers on total payment are consistently negative, although not precise enough to claim statistical significance. The upper bound of the effect of hiring a lawyer on total payment received is negative after fees in our preferred specification. This suggests that even in the most optimistic scenario, lawyers appear to reduce total recovery.
中文摘要
律师对其客户的价值因内生性问题而众所周知难以估计。我们利用对附带来源规则（CS规则）的修改作为聘请律师的工具变量，该修改要求以第一方保险赔付金额扣减审判赔偿金。我们的工具变量存在的问题是，对CS规则的修改对赔偿金额具有直接影响，因而违反了有效工具变量所要求的外生性约束。我们开发了一种新的识别与估计方法，将CS规则变更作为无效工具变量使用，并对律师的影响进行界值估计。我们发现，所估计影响的上界和下界均低于未对内生性进行校正的估计结果。我们对律师对总赔付额影响的估计始终为负，尽管精确度不足以声称具有统计显著性。在我们偏好的设定中，聘请律师对所得总赔付额影响的上界在扣除费用后为负。这表明，即使在最乐观的情形下，律师似乎也会降低总赔偿额。