Among 755,004 Philadelphia landlord--tenant records filed during 1969-2022, 396,163 residential cases involve tenants who appear exactly once in the observed docket. In unadjusted comparisons, single-appearance cases handled by high-volume plaintiff-side counsel are more likely to advance to the writ-of-possession and served-writ stages, but no more likely to end in default. Comparisons within the same plaintiff, and within the same plaintiff at the same property, show no broad premium on adverse case outcomes such as default, judgment, or fees. The clearer pattern is organizational: after a plaintiff adopts or switches into high-volume counsel, monthly filings rise by about 2-5% and the number of distinct buildings reached rises by a similar margin; near the prior-year top-10 attorney threshold, cases display local differences in default and enforcement; and continuances under specialist counsel are more closely linked to default. Non-flat pre-treatment trends and imprecise reverse-direction estimates from attorney exits restrict the strength of any causal claim. High-volume plaintiff-side counsel therefore functions as a mechanism of filing scale and procedural sequence, not as a uniform escalator of case outcomes or as a cause of any individual tenant becoming single-appearance.

翻译：在1969年至2022年提交的755,004份费城房东-租客记录中，有396,163起住宅案件涉及租客在案卷中仅出现一次。未经调整的比较显示，由高诉量原告律师处理的单次出庭案件更可能进入强制执行令和送达令阶段，但并不会更大概率以缺席判决告终。在同一原告内部以及同一原告在同一房产内的比较显示，高诉量律师对不利案件结果（如缺席判决、判决或费用）并无普遍加成。更清晰的模式体现在组织层面：原告聘请或转用高诉量律师后，月度申请量上升约2-5%，涉及的独立建筑数量也以类似幅度增加；在接近前一年前十名律师阈值时，案件在缺席判决和执行方面呈现局部差异；专业律师处理的延期案件与缺席判决关联性更强。非平坦的事前趋势以及律师退出估计的反向方向不精确性，限制了任何因果主张的力度。因此，高诉量原告律师行使的是案件规模与程序顺序的机制功能，而非案件结果的统一推进器，也不构成任何租客成为单次出庭的成因。