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arxiv: 2605.15165 · v1 · submitted 2026-05-14 · 💻 cs.CY · stat.AP

Recognition: no theorem link

Due Process on Hold: A Queueing Framework for Improving Access in SNAP

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Pith reviewed 2026-05-15 02:58 UTC · model grok-4.3

classification 💻 cs.CY stat.AP
keywords SNAPcall centersqueueing modelsdue processsocial safety netfluid approximationendogenous congestionaccess to services
0
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The pith

A queueing model shows that standard staffing rules understaff SNAP call centers because they ignore feedback from redials and abandonments.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper develops a queueing framework to assess access in SNAP call centers, where congestion leads to procedural denials that violate due process rights. It argues that common staffing rules fail to account for endogenous congestion created by applicants redialing or abandoning calls, resulting in persistent understaffing. Using a fluid approximation, the model derives steady-state metrics to evaluate combined changes in staffing and service delivery. Fitting the model to court-disclosed data allows for policy recommendations that could ensure applicants have a meaningful chance to complete their applications. This approach treats access failures as system-level dynamics rather than isolated algorithmic issues.

Core claim

Standard queueing guidance from Erlang-A that does not address endogenous congestion fundamentally understaffs, which could lead to persistent shortfalls in practice. The authors develop a queueing model incorporating redials and abandonment through which backlogs generate endogenous congestion. Using a fluid approximation, they derive steady-state performance metrics to analytically characterize the impacts of bundled staffing and service delivery changes, and fit the parameters to call-center data from court documents.

What carries the argument

A queueing model that incorporates redials and abandonment to capture endogenous congestion, analyzed through fluid approximation to derive steady-state performance metrics.

Load-bearing premise

The redials and abandonment behaviors observed in the Missouri court-disclosed data are stable and representative enough to support general policy recommendations for staffing and service changes across SNAP systems.

What would settle it

A direct comparison showing whether actual call completion rates, wait times, and procedural denial rates in a SNAP call center match the model's predictions after staffing increases based on the derived metrics.

Figures

Figures reproduced from arXiv: 2605.15165 by Andrew Daw, Angela Zhou, Chloe Pache.

Figure 1
Figure 1. Figure 1: Process flow diagram of a queueing theoretic model of the SNAP call center. [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Performance metrics vs staffing levels for different potential changes in call center system design. [PITH_FULL_IMAGE:figures/full_fig_p015_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Screenshot of call center dashboard B Dashboard Manuscript submitted to ACM [PITH_FULL_IMAGE:figures/full_fig_p020_3.png] view at source ↗
read the original abstract

The U.S. social safety net delivers essential services at mass scale, but access burdens persist, as congested contact or call centers serve as a primary mode of application completion and assistance. In Holmes v. Knodell, Missouri's SNAP call centers were so congested that nearly half of all application denials were procedural, caused by applicants' inability to complete required interviews, rather than underlying ineligibility. The judge ruled these system failures led to a violation of procedural due process. We propose a performance evaluation framework based on queueing models from operations research and management to assess and improve access in such systems. Operational access failures of call centers are distinct from prior automation failures in benefits provision. Emergent arbitrariness arises from interactions between system dynamics and access demand, rather than from an explicit algorithmic rule, making diagnosis and repair inherently system-level. We develop a queueing model that incorporates phenomena that distinguish social services from standard service domains, redials and abandonment, through which backlogs generate endogenous congestion. Standard queueing guidance from Erlang-A that does not address endogenous congestion fundamentally understaffs, which could lead to persistent shortfalls in practice. Using a fluid approximation, we derive steady-state performance metrics to analytically characterize the impacts of bundled staffing and service delivery changes. We fit model parameters to call-center data disclosed in court documents. Our queueing model can support ex-ante evaluation and design of access systems, inform policy levers for improving access, and provide evidence about whether applicants are afforded a meaningful opportunity to be served at scale.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The paper claims that standard Erlang-A staffing guidance for call centers understaffs SNAP systems by ignoring endogenous congestion generated by redials and abandonment; it develops a fluid-approximation queueing model, derives steady-state performance metrics, fits redial and abandonment rates to Missouri SNAP call-center logs disclosed in Holmes v. Knodell, and uses the model to characterize the effects of bundled staffing and service-delivery changes on access and due-process compliance.

Significance. If the fitted parameters prove stable and the fluid metrics are validated, the framework supplies an analytical, system-level tool for ex-ante evaluation of access interventions in large-scale social-service contact centers, directly addressing procedural-due-process failures that arise from congestion rather than explicit rules.

major comments (2)
  1. [Abstract] Abstract and model-description section: the headline claim that Erlang-A 'fundamentally understaffs' is obtained by comparing steady-state metrics whose redial and abandonment rates are taken directly from a single court-disclosed Missouri dataset; no cross-validation, sensitivity analysis across jurisdictions, or out-of-sample check is reported, so the quantitative gap between the two models rests on untested parameter stability.
  2. [Model section] Fluid-approximation derivation: the steady-state performance metrics are stated to be derived analytically, yet the manuscript supplies neither the explicit fluid equations nor any error-bound or convergence analysis relative to the underlying stochastic process, making it impossible to assess how large the reported staffing shortfall remains under realistic parameter perturbations.
minor comments (1)
  1. [Abstract] Notation for the fluid model parameters (e.g., redial rate, abandonment probability) should be introduced once with clear definitions and then used consistently; several instances in the abstract and results paragraphs use informal phrasing that obscures the mapping to the fitted values.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback on our manuscript. We address each major comment below and will revise the paper to incorporate additional analyses and derivations for greater transparency and robustness.

read point-by-point responses
  1. Referee: [Abstract] Abstract and model-description section: the headline claim that Erlang-A 'fundamentally understaffs' is obtained by comparing steady-state metrics whose redial and abandonment rates are taken directly from a single court-disclosed Missouri dataset; no cross-validation, sensitivity analysis across jurisdictions, or out-of-sample check is reported, so the quantitative gap between the two models rests on untested parameter stability.

    Authors: We agree that the analysis relies on parameters fitted from a single Missouri dataset disclosed in court documents from Holmes v. Knodell. This provides a grounded case study of a real-world SNAP system but limits generalizability. In the revision, we will add a dedicated sensitivity analysis varying redial and abandonment rates over plausible ranges drawn from call-center literature, and we will explicitly discuss how the staffing shortfall between the models persists under these perturbations. This addresses the concern about untested parameter stability without requiring new data sources. revision: yes

  2. Referee: [Model section] Fluid-approximation derivation: the steady-state performance metrics are stated to be derived analytically, yet the manuscript supplies neither the explicit fluid equations nor any error-bound or convergence analysis relative to the underlying stochastic process, making it impossible to assess how large the reported staffing shortfall remains under realistic parameter perturbations.

    Authors: We appreciate this observation on the presentation of the model. The fluid equations were derived using standard many-server queueing approximations for systems with abandonment and redials, but were not displayed in full in the main text. In the revised manuscript, we will include the complete set of fluid differential equations (for queue length, abandonment, and redial flows) in a new appendix subsection, along with a brief discussion of convergence to the stochastic process based on established fluid-limit results in the queueing literature. We will also report simulation-based validation of the approximation error under the fitted parameters to quantify robustness of the staffing gap. revision: yes

Circularity Check

0 steps flagged

No significant circularity; derivation uses independent fluid model on externally fitted parameters

full rationale

The paper's derivation chain proceeds from a standard queueing model augmented with redials and abandonment, through a fluid approximation to obtain steady-state metrics, to numerical characterization of staffing impacts. Parameters are estimated from court-disclosed call-center logs (external data source), after which the model produces performance predictions. No equation reduces a claimed prediction to its own fitted inputs by construction, no self-citation supplies a load-bearing uniqueness result, and no ansatz is smuggled via prior work. The central claim that Erlang-A understaffs is a model-derived comparison whose quantitative content depends on the external data rather than tautological re-expression of the inputs. The analysis is therefore self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

1 free parameters · 2 axioms · 0 invented entities

The central claim rests on standard queueing theory assumptions plus parameters fitted to limited court data; no new entities are postulated.

free parameters (1)
  • Redial and abandonment rates
    Fitted to call-center data disclosed in court documents to parameterize the model dynamics.
axioms (2)
  • domain assumption Fluid approximation yields valid steady-state performance metrics for the multi-server system with abandonment and redials
    Invoked to derive analytical characterizations of staffing impacts.
  • domain assumption Call-center dynamics can be captured by standard queueing primitives extended with redial and abandonment
    Core modeling choice distinguishing social-service call centers from conventional service systems.

pith-pipeline@v0.9.0 · 5575 in / 1439 out tokens · 60941 ms · 2026-05-15T02:58:45.365532+00:00 · methodology

discussion (0)

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Reference graph

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