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Evolution and determinants of firm-level systemic risk in local production networks

T0 review · 3 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Using yearly snapshots of the Budapest production network, this paper argues that firms' rewiring of supply links during COVID-19 made the economy more resilient than a randomized network with the same firm-level constraints would predict.

desk verdict Solid descriptive study of Budapest production networks; the headline resilience-rewiring claim outruns the evidence because the empirical-null gap starts in 2018, before COVID. read the letter →

arxiv 2506.21426 v2 pith:2NKUU2ZX submitted 2025-06-26 physics.soc-ph cs.SIecon.GNphysics.data-anq-fin.ECq-fin.RM

classification physics.soc-phcs.SIecon.GNphysics.data-anq-fin.ECq-fin.RM PACS 89.65.Gh
keywords systemicriskproductionnetworksfirm-leveldatanullmodelsmaximumentropyCOVID-19supplychainrewiringinternationaltrade
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper asks whether firms can make an economy safer by actively reconfiguring their supply relationships during a crisis, and measures this in the Budapest production network year by year from 2015 to 2022. Each firm carries a systemic-risk score: the total output the local economy would lose if that firm failed, computed by simulating the propagation of its failure through suppliers and customers. The paper compares these empirical scores against a maximum-entropy null model that randomizes the network while preserving every firm's sector-level inputs and outputs, a stand-in for a market that adapts no further than its production structure dictates. Empirical risk tracks the null benchmark closely until 2020, then drops significantly below it even as the benchmark rises, which the authors read as evidence that firms rewired their links under pandemic pressure into configurations that spread damage less. A sympathetic reader would care because the result suggests resilience is something firms actively produce in a crisis, not just a fixed property of the network, and because the gap between real and randomized networks gives a generic way to spot that adaptation.

What carries the argument

Two objects carry the argument. The first is the Economic Systemic Risk Index (ESRI), which assigns each firm the output-weighted total production loss of the network when that firm fails: $\mathrm{ESRI}_i = \sum_j \frac{s^{\mathrm{out}}_j}{\sum_l s^{\mathrm{out}}_l}\left[1 - h_j(n^*)\right]$, where $h_j(n^*)$ is the fraction of original production firm $j$ can still maintain after upstream and downstream shocks have iterated to a stable state under a generalized Leontief production function. The second is the stripe-corrected gravity model (s-GM), a heuristic maximum-entropy null model that generates an ensemble of randomized networks (100 per year) while preserving each firm's total output and its input quantities by sector; the ensemble incarnates a Walrasian-equilibrium assumption in which agents care only about final allocations, not the network that realizes them. The paper's detection strategy is to compare each year's empirical ESRI distribution against this equilibrium benchmark, and then to regress empirical ESRI on the null-model value plus local-trade and international-trade variables with firm fixed effects, so that the regression residuals reveal which firm attributes carry the part of systemic risk the null model cannot explain.

What would settle it

Re-run the 2020–2022 comparison after removing the null model's known upward bias for the most connected firms, for instance by restricting the comparison to firms matched on size and sector or by explicitly subtracting the bias, and see whether empirical systemic risk still falls significantly below the corrected benchmark; if the gap disappears, the adaptive-rewiring interpretation is falsified. A complementary check measures actual supplier and customer turnover per firm in the pandemic years and asks whether the firms whose risk fell most are the ones whose link portfolios demonstrably changed.

Watch

Extended reading notes

Core claim

The paper's central claim is that firm-level systemic risk in the Hungarian production network behaves like the random-network benchmark during normal times and then becomes significantly smaller than it from 2020 onward, even though the benchmark itself keeps rising. Because the null model already respects each firm's production structure, total sales and sector-level purchases are preserved, this divergence cannot be explained by the growth of firms or the entry of small firms alone; the authors attribute it to adaptive behavior, namely firms finding alternative suppliers and customers under pandemic restrictions and import bans, and thereby damping how far a failure would propagate. Accompanying the divergence is a structural shift in the composition of the riskiest firms: the plateau of top-0.1% ESRI firms becomes dominated by firms that enable exchange itself, most prominently postal services, a reconfiguration the null model does not reproduce. The regression analysis rounds out the picture, showing that international trade volumes, insignificant before 2020, become strong predictors of firm-level systemic risk during the crisis, with imports and exports exerting opposing effects through the supply and demand channels respectively.

Load-bearing premise

The claim that the post-2020 drop in systemic risk comes from firms' adaptive rewiring depends on treating the randomized null model as a fair benchmark: if that model's known tendency to overestimate the risk of the biggest firms, or the 2018 VAT reporting change that expanded the dataset, explains the gap instead, the rewiring conclusion loses its footing.

Editorial extensions

If this is right

  • Systemic risk is time-dependent: the pandemic years show that a firm's danger to the economy can be reduced by its own rewiring, so pre-crisis network measurements alone will overstate post-crisis risk.
  • The gap between an empirical network and its sector-constrained random benchmark becomes a working indicator of adaptation: when observed risk falls below the null expectation, purposeful restructuring rather than random churn is the likely cause.
  • The identity of the most dangerous firms can change abruptly in a crisis: postal services and other exchange-enabling sectors rising into the top-risk plateau means crisis monitoring should track the connectors, not just the traditional giants.
  • International trade affects local systemic risk mainly when trade itself is disrupted: import and export volumes become significant predictors of firm risk during COVID-19, with imports complementing domestic supply and exports substituting for local revenue pushing risk in opposite directions.
  • If the divergence is real, average-risk statistics understate the story: the economically meaningful signal is risk relative to the equilibrium benchmark, which fell even while the absolute number of firms and transactions kept growing.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct test the paper motivates but does not run: measure supplier and customer turnover for each firm in 2020–2022 and verify that the firms whose ESRI fell most relative to the null model are the same firms whose link portfolios demonstrably changed; that would make the rewiring mechanism observable rather than inferred.
  • The adaptive-rewiring reading predicts a cross-country gradient: economies whose pandemic restrictions most severely constrained imports and exports should show the largest empirical-versus-null ESRI gaps, since forced import substitution would drive more rewiring.
  • Part of the post-2020 gap could be mechanical rather than adaptive: the null model is known to overestimate the risk of the most connected firms, and the 2018 VAT reporting reform changed which firms appear in the data, so quantifying how much of the divergence survives those corrections would sharpen or shrink the rewiring conclusion.
  • The paper's framing suggests a monitoring design consequence: after a crisis rewires a network, the newly central exchange-enabling firms become single points of failure, so resilience monitoring should follow the post-shock network rather than the pre-crisis list of high-risk firms.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The paper studies the evolution of firm-level systemic risk (ESRI) in the Budapest production network from 2015 to 2022, using VAT transaction data. The authors compute ESRI for each firm and benchmark the empirical values against an ensemble of stripe-corrected gravity model (s-GM) null networks that preserve each firm's sector-level total input and output flows. They report that the set of highest-risk firms changes during COVID-19, that the empirical mean ESRI aligns with the null until 2020 but becomes significantly lower afterwards, and that international trade becomes a significant predictor of firm-level ESRI during the pandemic. Regression analysis with firm fixed effects and year dummies is used to relate ESRI to null-model ESRI, local trade strengths, essentiality, and import/export volumes.

Significance. If the central claim is correct, the paper would provide one of the first longitudinal accounts of how a production network's systemic risk responds to a major shock through adaptive rewiring. The dataset is rich, the temporal span is unusual, and the use of a constrained null model to benchmark empirical ESRI is methodologically appropriate in principle. The paper also conducts extensive robustness checks (pooled OLS, cross-sectional regressions, supplementary analyses) and is transparent about computational limitations. However, the main empirical-null comparison is vulnerable to a known bias in the null model and a concurrent data-coverage break, and the regression design does not fully separate the COVID-specific shift from earlier level changes. These issues are central to the paper's headline claim, so the current evidence is insufficient to establish the adaptive-rewiring narrative.

major comments (3)
  1. [Empirical vs null model values of ESRI (Fig. 3C)] The central claim that empirical ESRI becomes significantly smaller than the null after 2020 is undermined by the 2018 data-coverage break and the known upward bias of the s-GM for high-risk firms. The authors themselves note that the model 'overestimates ESRI of the most risky firms' (Fig. 3B) and that 'from 2018 onward, the model ESRI becomes significantly higher than the real one.' The 2018 jump coincides with the RTIR/VAT reporting changes that introduce many small firms, and the s-GM's bias grows when low-connectivity small firms become disconnected in model samples (ref. 62). The paper does not quantify how much of the 2020-2022 gap is explained by this bias or compare the pandemic-period gap against an extrapolation of the 2018-2019 bias trend. Without such a counterfactual, the attribution of the divergence to adaptive rewiring is unsupported.
  2. [Regression framework (Table 1; Supplementary S16)] The regression analysis includes ESRImodel as a covariate, which controls for cross-sectional levels but not for the year-specific mean shift that drives Figure 3C. The pooled OLS regressions in Supplementary S16 show year dummies that decline monotonically from 2018 onward (-0.027 in 2018, -0.041 in 2019, -0.043 in 2020, -0.047 in 2021, -0.053 in 2022), meaning the empirical-null gap is already present before the pandemic. The interpretation that the import/export coefficients are COVID-specific therefore relies on a before/after split that is not cleanly identified by the data, because the post-2018 sample composition changes confound the pandemic effect.
  3. [Methods, Eq. (4) and Eq. (1)] The s-GM preserves, on average, each firm's total out-strength and in-strength by sector, and the ESRI definition (Eq. 1) weights firms' output reductions by their out-strengths. The pre-2020 agreement between empirical and null mean ESRI is therefore partly a calibration artifact: the null model is built to reproduce the very strength sequences that dominate ESRI. This does not invalidate the null-model comparison, but it means the normal-times alignment cannot serve as independent evidence that the s-GM is an unbiased benchmark during the crisis. To support the adaptive-rewiring claim, the authors should report an analysis that holds firm composition fixed (for example by reweighting or subsetting the 2018-2022 samples to match the 2015-2017 firm distribution) and show that the divergence persists.
minor comments (4)
  1. [Table 2] The 2017 pre-filtering transaction count (25,494) is an order of magnitude smaller than the 2016 (225,165) and 2018 (1,373,207) values; this appears to be a typo and should be corrected or explained.
  2. [Figure 3C] The caption refers to a shaded area corresponding to standard deviations but does not specify whether the shading is shown for both empirical and null series; please clarify in the figure or legend.
  3. [Results, 'Sector composition of ESRI plateaux'] The text says that upstream ESRI shows 'large positive variations' starting from 2020, but earlier in the same paragraph it states that the plateau shape remains consistent until 2019; the transition from stability to step-like structure is described only verbally and would benefit from a quantitative measure of the variation.
  4. [References] Reference 62 is cited for the claim that small firms may become disconnected in s-GM samples, but that paper addresses critical density for network reconstruction more generally; citing a more directly relevant source or expanding the explanation would help the reader.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the empirical-versus-null ESRI comparison is a benchmark validation, not an identity, and the crisis-period attribution is an interpretation rather than a circular derivation.

full rationale

The paper's derivation chain is self-contained and no step reduces to its own inputs. The s-GM null model is calibrated to sector-level strengths and link counts, and ESRI is then computed on the randomized networks; ESRI is not one of the constrained quantities, so the close empirical-null agreement in 2015-2017 is a nontrivial validation rather than an identity. The crisis-period divergence (Fig. 3C) is an empirical residual between the observed network and the calibrated benchmark; the paper explicitly discusses that the s-GM overestimates ESRI for the most risky firms and that the gap grows from 2018 onward, so the attribution to adaptive rewiring is an interpretation subject to confounds (coverage break, model bias) rather than a circular derivation. The regressions include ESRImodel as a covariate, which is a benchmark control, not the target quantity itself, and the import/export results are separate empirical associations. Self-citations to refs 54 and 55 for the s-GM and its normal-time ESRI performance are not load-bearing because the same validation is reproduced in Figs. 3B, 3E and the supplementary rankings. Validity concerns about the null model's upward bias and the 2018 RTIR coverage break are correctness risks, not circularity.

Assumptions & free parameters 5 free parameters · 5 assumptions · 0 invented entities

The central claims rest on the null model calibration, the ESRI production-function assumptions, and the data filtering choices. The s-GM sector parameters and technical coefficients are fitted to the empirical data, so the normal-time match with the null is not independent of the network structure being tested.

free parameters (5)
  • z_g (s-GM sector gravity parameters) = not reported (one per NACE sector)
    Fitted to reproduce the empirical number of outgoing links per sector in the s-GM; these parameters determine the null network ensemble and thus the null ESRI values.
  • ESRI shock-propagation convergence threshold = not reported
    The iteration stops at n* when a stable state is reached; the threshold affects ESRI magnitudes but its exact setting is not given.
  • technical coefficients of Leontief production function = calibrated on empirical network (from ref. 36)
    Used in the ESRI downstream shock propagation; calibrated to empirical data, so part of the risk measure itself is fitted.
  • data filtering thresholds = VAT >= 1M HUF; employees > 11 or kout > 2; Budapest HQ only
    These thresholds define the analyzed network and affect all ESRI values, correlations, and regressions.
  • plateau selection fraction = top 0.1% of ESRI ranking
    Defines the set of 'most risky' firms in the plateau analysis.
assumptions (5)
  • domain assumption Each firm produces exactly one product, determined by its NACE4 code.
    State in the 'Hungarian production network' section; this assumption is necessary for the sector-specific constraints in s-GM and for the essentiality matrix.
  • domain assumption Shock propagation follows a generalized Leontief production function where inputs from essential sectors are treated differently from non-essential ones.
    This is the core ESRI mechanism, taken from refs. 36 and 17, and is assumed in the calculation of the dependent variable.
  • domain assumption s-GM fitness ansatz: firm connectivity is proportional to its strength.
    This is the basis of the gravity model link probability in Eq. (2); it is a modeling assumption, not a derived result.
  • domain assumption Networks can be approximated as equilibrium (Walrasian) configurations in normal times.
    The paper interprets s-GM as representing equilibrium configurations; this framing is used to interpret deviations as resilience.
  • standard math The null model ensemble of 100 networks is representative.
    The paper averages over 100 realizations; this is a numerical sampling assumption.

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Pith. "Pith review of Evolution and determinants of firm-level systemic risk in local production networks." pith.science (2026). https://pith.science/paper/2NKUU2ZX

@misc{pith2026250621426,
  author       = {Pith},
  title        = {Pith review of: Evolution and determinants of firm-level systemic risk in local production networks},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/2NKUU2ZX}},
  note         = {Machine review of arXiv:2506.21426}
}
read the original abstract

Recent crises like the Covid-19 pandemic and geopolitical tensions have exposed vulnerabilities and caused disruptions of supply chains, leading to product shortages, increased costs, and economic instability. This has prompted growing efforts to assess systemic risk, namely the effects of firm disruptions on entire economies. However, the ability of firms to react to crises by rewiring their supply links has been largely overlooked, limiting our understanding of production networks resilience. Here, we study dynamics and determinants of firm-level systemic risk in the Hungarian economy from 2015 to 2022. We benchmark our results to a heuristic maximum entropy null model that generates randomized production networks while preserving the total input (demand) and output (supply) of each firm at the sector level. We show that the fairly stable set of firms with highest systemic risk undergoes a structural change during Covid-19, as those enabling economic exchanges become key players in the economy -- a pattern not reproduced by the null model. Although empirical systemic risk closely matches the null value prior to the pandemic, it becomes significantly lower afterwards, reflecting the emergence of a more resilient economy driven by firms' adaptive behavior. Furthermore, firms' international trade volume (being itself a channel of potential disruption) becomes a significant predictor of their systemic risk. However, international linkages alone cannot fully explain the observed trends, as imports and exports exert opposing effects on local systemic risk through the supply and demand channels.

Figures

Figures reproduced from arXiv: 2506.21426 by the authors.

Figure 1
Figure 1. Empirical and null model networks are compared before and during the COVID-19 crisis, to study the evolution of economic systemic risk and understand the role of international trade. We start with temporal snapshots of the empirical production network. The top of the figure shows the network of a sample of the same 1000 nodes, before and during the crisis. Firms are colored according to the presence (green) or absen… view at source ↗
Figure 2
Figure 2. Time evolution of topological properties and systemic risk of the empirical production networks. A) Number of nodes (firms), links (transactions) and density of the local Budapest production network in the considered time range. B) Probability distributions of out-degree (number of customers per firm) for all yearly production networks. C) Probability distribution of in-degree (number of suppliers) for all yearly pr… view at source ↗
Figure 3
Figure 3. Empirical vs null model ESRI values. A) Matrix of Pearson correlation coefficients for null ESRI values of firms among different years. B) Empirical vs null ESRI values of individual firms for 2019. The size of each point corresponds to the firm’s number of employees, here taken as proxy for size. C) Mean value of ESRI for empirical and null networks. Shaded area refers to standard deviations (which are larger for t… view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: ESRI plateaux analysis. A) Representation of the empirical network among plateau firms, with node size proportional to ESRI values and color identifying the NACE2 sector. B) Matrix of Jaccard indices quantifying the overlap among the sets of empirical plateaux firms be…

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Works this paper leans on

74 extracted references · 50 canonical work pages

  1. [1]

    & Syverson, C

    Atalay, E., Hortaçsu, A., Roberts, J. & Syverson, C. Network structure of production. Proc. Natl. Acad. Sci. 108, 5199–5202, DOI: https://doi.org/10.1073/pnas.1015564108 (2011)

  2. [2]

    L˝orincz, L., Juhász, S. & O. Szabó, R. Business transactions and ownership ties between firms. Netw. Sci. 12, 1–20, DOI: DOI:10.1017/nws.2023.19 (2024)

  3. [3]

    McNerney, J., Savoie, C., Caravelli, F., Carvalho, V . M. & Farmer, J. D. How production networks amplify economic growth. Proc. Natl. Acad. Sci. 119, e2106031118, DOI: 10.1073/pnas.2106031118 (2022)

  4. [4]

    Zoltán Elekes, R. B. & Lengyel, B. Foreign-owned firms as agents of structural change in regions. Reg. Stud. 53, 1603–1613, DOI: 10.1080/00343404.2019.1596254 (2019). https://doi.org/10.1080/00343404.2019.1596254

  5. [5]

    Choi, T. Y . & Krause, D. R. The supply base and its complexity: Implications for transaction costs, risks, responsiveness, and innovation. J. operations management 24, 637–652, DOI: https://doi.org/10.1016/j.jom.2005.07.002 (2006)

  6. [6]

    W., Blackhurst, J., Rungtusanatham, M

    Craighead, C. W., Blackhurst, J., Rungtusanatham, M. J. & Handfield, R. B. The severity of supply chain disruptions: Design characteristics and mitigation capabilities. Decis. Sci. 38, 131–156, DOI: https://doi.org/10.1111/j.1540-5915.2007.00151.x (2007)

  7. [7]

    & Chen, Y .-Y

    Cheng, C.-Y ., Chen, T.-L. & Chen, Y .-Y . An analysis of the structural complexity of supply chain networks.Appl. Math. Model. 38, 2328–2344, DOI: https://doi.org/10.1016/j.apm.2013.10.016 (2014)

  8. [8]

    G., Soundar Kumara & Raghavan, U

    Amit Surana, M. G., Soundar Kumara & Raghavan, U. N. Supply-chain networks: a complex adaptive systems perspective. Int. J. Prod. Res. 43, 4235–4265, DOI: 10.1080/00207540500142274 (2005)

Show all 74 references
  1. [9]

    V okurka, R. J. & Lummus, R. R. The role of just-in-time in supply chain management. The Int. J. Logist. Manag. 11, 89–98, DOI: 10.1108/09574090010806092 (2000)

  2. [10]

    & Sauvagnat, J

    Barrot, J.-N. & Sauvagnat, J. Input specificity and the propagation of idiosyncratic shocks in production networks. The Q. J. Econ. 131, 1543–1592 (2016)

  3. [11]

    & Todo, Y

    Inoue, H. & Todo, Y . Firm-level propagation of shocks through supply-chain networks.Nat. Sustain. 2, 841–847, DOI: https://doi.org/10.1038/s41893-019-0351-x (2019)

  4. [12]

    & Zennaro, I

    Aldrighetti, R., Battini, D., Ivanov, D. & Zennaro, I. Costs of resilience and disruptions in supply chain network design models: A review and future research directions. Int. J. Prod. Econ. 235, 108103, DOI: https://doi.org/10.1016/j.ijpe.2021. 108103 (2021)

  5. [13]

    M., Nirei, M., Saito, Y

    Carvalho, V . M., Nirei, M., Saito, Y . U. & Tahbaz-Salehi, A. Supply chain disruptions: Evidence from the Great East Japan Earthquake. The Q. J. Econ. 136, 1255–1321, DOI: https://doi.org/10.1093/qje/qjaa044 (2021)

  6. [14]

    & Wei, D

    Rose, A., Chen, Z. & Wei, D. The economic impacts of russia–ukraine war export disruptions of grain commodities. Appl. Econ. Perspectives Policy45, 645–665, DOI: https://doi.org/10.1002/aepp.13351 (2023). https://onlinelibrary.wiley.com/ doi/pdf/10.1002/aepp.13351. 12/39

  7. [15]

    Guan, D. et al. Global supply-chain effects of covid-19 control measures. Nat. Hum. Behav. 4, 577–587, DOI: https: //doi.org/10.1038/s41562-020-0896-8 (2020)

  8. [16]

    K., Kaisar, S

    Chowdhury, P., Paul, S. K., Kaisar, S. & Moktadir, M. A. Covid-19 pandemic related supply chain studies: A systematic review. Transp. Res. Part E: Logist. Transp. Rev.148, 102271, DOI: https://doi.org/10.1016/j.tre.2021.102271 (2021)

  9. [17]

    M., Lafond, F

    Pichler, A., Pangallo, M., del Rio-Chanona, R. M., Lafond, F. & Farmer, J. D. Production networks and epidemic spreading: How to restart the UK economy? arXiv preprint arXiv:2005.10585 DOI: https://doi.org/10.48550/arXiv.2005.10585 (2020)

  10. [18]

    & Farmer, J

    Pichler, A. & Farmer, J. D. Simultaneous supply and demand constraints in input–output networks: the case of covid-19 in Germany, Italy, and Spain. Econ. Syst. Res. 34, 273–293, DOI: https://doi.org/10.1080/09535314.2021.1926934 (2022)

  11. [19]

    & Schönberger, J

    Ivanov, D., Tsipoulanidis, A. & Schönberger, J. Supply Chain Risk Management and Resilience , 485–520 (Springer International Publishing, Cham, 2021)

  12. [20]

    Input-output economics (Oxford University Press, 1986)

    Leontief, W. Input-output economics (Oxford University Press, 1986)

  13. [21]

    Miller, R. E. & Blair, P. D. Input-output analysis: foundations and extensions (Cambridge university press, 2009)

  14. [22]

    Transmission of Domestic and External Shocks through Input-Output Network: Evidence from Korean Industries

    Lee, D. Transmission of Domestic and External Shocks through Input-Output Network: Evidence from Korean Industries. IMF Working Papers 2019/117, International Monetary Fund (2019)

  15. [23]

    Contreras, M. G. A. & Fagiolo, G. Propagation of economic shocks in input-output networks: A cross-country analysis (2014). 1401.4704

  16. [24]

    M., Ozdaglar, A

    Acemoglu, D., Carvalho, V . M., Ozdaglar, A. & Tahbaz-Salehi, A. The network origins of aggregate fluctuations. Econometrica 80, 1977–2016, DOI: https://doi.org/10.3982/ECTA9623 (2012)

  17. [25]

    Carvalho, V . M. & Tahbaz-Salehi, A. Production networks: A primer. Annu. Rev. Econ. 11, 635–663, DOI: https: //doi.org/10.1146/annurev-economics-080218-030212 (2019)

  18. [26]

    The granular origins of aggregate fluctuations

    Gabaix, X. The granular origins of aggregate fluctuations. Econometrica 79, 733–772, DOI: https://doi.org/10.3982/ ECTA8769 (2011)

  19. [27]

    & Lafond, F

    Bacilieri, A., Borsos, A., Astudillo-Estevez, P. & Lafond, F. Firm-level production networks: what do we (really) know? Tech. Rep. 2023-08, INET Oxford Working Paper (2023)

  20. [28]

    On aggregation problems in input-output analysis.The Rev

    Morimoto, Y . On aggregation problems in input-output analysis.The Rev. Econ. Stud. 37, 119–126, DOI: 10.2307/2296502 (1970)

  21. [29]

    & Thurner, S

    Diem, C., Borsos, A., Reisch, T., Kertész, J. & Thurner, S. Estimating the loss of economic predictability from aggregating firm-level production networks. PNAS nexus 3, pgae064, DOI: https://doi.org/10.1093/pnasnexus/pgae064 (2024)

  22. [30]

    W., Blackhurst, J., Rungtusanatham, M

    Craighead, C. W., Blackhurst, J., Rungtusanatham, M. J. & Handfield, R. B. The Severity of Supply Chain Disruptions: Design Characteristics and Mitigation Capabilities. Decis. Sci. 38, 131–156, DOI: https://doi.org/10.1111/j.1540-5915. 2007.00151.x (2007)

  23. [31]

    snowball effect

    ´Swierczek, A. The impact of supply chain integration on the “snowball effect” in the transmission of disruptions: An empirical evaluation of the model. Int. J. Prod. Econ. 157, 89–104, DOI: https://doi.org/10.1016/j.ijpe.2013.08.010 (2014). The International Society for Inven...

  24. [32]

    & Dolgui, A

    Ivanov, D., Sokolov, B. & Dolgui, A. The ripple effect in supply chains: trade-off ‘efficiency-flexibility-resilience’in disruption management. Int. J. Prod. Res. 52, 2154–2172, DOI: https://doi.org/10.1080/00207543.2013.858836 (2014)

  25. [33]

    B., Shi, Z

    Shao, B. B., Shi, Z. M., Choi, T. Y . & Chae, S. A data-analytics approach to identifying hidden critical suppliers in supply networks: Development of nexus supplier index. Decis. Support. Syst. 114, 37–48, DOI: https://doi.org/10.1016/j.dss.2018. 08.008 (2018)

  26. [34]

    & Talluri, S

    Käki, A., Salo, A. & Talluri, S. Disruptions in supply networks: A probabilistic risk assessment approach. J. Bus. Logist. 36, 273–287, DOI: https://doi.org/10.1111/jbl.12086 (2015)

  27. [35]

    & Tiwari, A

    Ledwoch, A., Brintrup, A., Mehnen, J. & Tiwari, A. Systemic risk assessment in complex supply networks. IEEE Syst. J. 12, 1826–1837, DOI: 10.1109/JSYST.2016.2596999 (2018)

  28. [36]

    & Thurner, S

    Diem, C., Borsos, A., Reisch, T., Kertész, J. & Thurner, S. Quantifying firm-level economic systemic risk from nation-wide supply networks. Sci. reports 12, 1–13, DOI: https://doi.org/10.1038/s41598-022-11522-z (2022)

  29. [37]

    & Gao, J

    Wang, Y ., Hong, A., Li, X. & Gao, J. Marketing innovations during a global crisis: A study of china firms’ response to covid-19. J. Bus. Res. 116, 214–220, DOI: https://doi.org/10.1016/j.jbusres.2020.05.029 (2020). 13/39

  30. [38]

    Belhadi, A. et al. Manufacturing and service supply chain resilience to the covid-19 outbreak: Lessons learned from the automobile and airline industries. Technol. Forecast. Soc. Chang.163, 120447, DOI: https://doi.org/10.1016/j.techfore. 2020.120447 (2021)

  31. [39]

    G., Wagner, S

    Klöckner, M., Schmidt, C. G., Wagner, S. M. & Swink, M. Firms’ responses to the covid-19 pandemic. J. Bus. Res. 158, 113664, DOI: https://doi.org/10.1016/j.jbusres.2023.113664 (2023)

  32. [40]

    & Blackhurst, J

    Zhao, K., Zuo, Z. & Blackhurst, J. V . Modelling supply chain adaptation for disruptions: An empirically grounded complex adaptive systems approach. J. Oper. Manag. 65, 190–212, DOI: https://doi.org/10.1002/joom.1009 (2019)

  33. [41]

    M., Petersen, K

    Bode, C., Wagner, S. M., Petersen, K. J. & Ellram, L. M. Understanding responses to supply chain disruptions: Insights from information processing and resource dependence perspectives. Acad. Manag. J. 54, 833–856, DOI: 10.5465/amj. 2011.64870145 (2011)

  34. [42]

    & Macdonald, J

    Bode, C. & Macdonald, J. R. Stages of supply chain disruption response: Direct, constraining, and mediating factors for impact mitigation. Decis. Sci. 48, 836–874, DOI: https://doi.org/10.1111/deci.12245 (2017)

  35. [43]

    Krammer, S. M. Navigating the new normal: Which firms have adapted better to the covid-19 disruption? Technovation 110, 102368, DOI: https://doi.org/10.1016/j.technovation.2021.102368 (2022)

  36. [44]

    & Parast, M

    Sabahi, S. & Parast, M. M. Firm innovation and supply chain resilience: a dynamic capability perspective. Int. J. Logist. Res. Appl. 23, 254–269, DOI: 10.1080/13675567.2019.1683522 (2020)

  37. [45]

    & El Omri, A

    Xu, Z., Elomri, A., Kerbache, L. & El Omri, A. Impacts of covid-19 on global supply chains: Facts and perspectives. IEEE Eng. Manag. Rev. 48, 153–166, DOI: 10.1109/EMR.2020.3018420 (2020)

  38. [46]

    & Marchi, V

    Panwar, R., Pinkse, J. & Marchi, V . D. The future of global supply chains in a post-covid-19 world.California Manag. Rev. 64, 5–23, DOI: 10.1177/00081256211073355 (2022)

  39. [47]

    & Garlaschelli, D

    Squartini, T. & Garlaschelli, D. Analytical maximum-likelihood method to detect patterns in real networks. New J. Phys. 13, 083001, DOI: https//doi.org/10.1088/1367-2630/13/8/083001 (2011)

  40. [48]

    Cimini, G. et al. The statistical physics of real-world networks. Nat. Rev. Phys. 1, 58–71, DOI: https://doi.org/10.1038/ s42254-018-0002-6 (2019)

  41. [49]

    & Garlaschelli, D

    Squartini, T., Van Lelyveld, I. & Garlaschelli, D. Early-warning signals of topological collapse in interbank networks. Sci. Reports 3, 3357, DOI: https://doi.org/10.1038/srep03357 (2013)

  42. [50]

    & Challet, D

    Gualdi, S., Cimini, G., Primicerio, K., Di Clemente, R. & Challet, D. Statistically validated network of portfolio overlaps and systemic risk. Sci. Reports 6, 39467, DOI: 10.1038/srep39467 (2016)

  43. [51]

    & Zaccaria, A

    Cimini, G., Carra, A., Didomenicantonio, L. & Zaccaria, A. Meta-validation of bipartite network projections. Commun. Phys. 5, 76, DOI: 10.1038/s42005-022-00856-9 (2022)

  44. [52]

    & Petrocchi, M

    Pratelli, M., Saracco, F. & Petrocchi, M. Entropy-based detection of twitter echo chambers. PNAS Nexus 3, pgae177, DOI: 10.1093/pnasnexus/pgae177 (2024). https://academic.oup.com/pnasnexus/article-pdf/3/5/pgae177/58004712/pgae177.pdf

  45. [53]

    & Cimini, G

    Ferracci, A. & Cimini, G. Systemic risk in interbank networks: disentangling balance sheets and network effects (2022). 2109.14360

  46. [54]

    Ialongo, L. N. et al. Reconstructing firm-level interactions in the dutch input–output network from production constraints. Sci. Reports 12, 1–12, DOI: https://doi.org/10.1038/s41598-022-13996-3 (2022)

  47. [55]

    Fessina, M. et al. Inferring firm-level supply chain networks with realistic systemic risk from industry sector-level data (2024). 2408.02467

  48. [56]

    & Viaggiu, S

    Bargigli, L., Lionetto, A. & Viaggiu, S. A statistical test of walrasian equilibrium by means of complex networks theory. J. Stat. Phys. 165, 351–370 (2016)

  49. [57]

    Bardoscia, M. et al. The physics of financial networks. Nat. Rev. Phys. 3, 490–507, DOI: 10.1038/s42254-021-00322-5 (2021)

  50. [58]

    & Stancsics, M

    Borsos, A. & Stancsics, M. Unfolding the hidden structure of the Hungarian multi-layer firm network. Tech. Rep., Magyar Nemzeti Bank (Central Bank of Hungary) (2020)

  51. [59]

    Your companion guide to international statistical classifications

    EUROSTAT. Your companion guide to international statistical classifications. section iv - description of the main economic classifications (2021)

  52. [60]

    Serafino, M. et al. True scale-free networks hidden by finite size effects. Proc. Natl. Acad. Sci. 118, e2013825118, DOI: 10.1073/pnas.2013825118 (2021). https://www.pnas.org/doi/pdf/10.1073/pnas.2013825118. 14/39

  53. [61]

    & Thurner, S

    Reisch, T., Borsos, A. & Thurner, S. Supply chain network rewiring dynamics at the firm-level, DOI: 10.48550/arXiv.2503. 20594 (2025)

  54. [62]

    & Garlaschelli, D

    Gabrielli, A., Macchiati, V . & Garlaschelli, D. Critical density for network reconstruction. In From Computational Logic to Computational Biology: Essays Dedicated to Alfredo Ferro to Celebrate His Scientific Career, 223–249, DOI: https://doi.org/10.1007/978-3-031-55248-9_11 ...

  55. [63]

    & Lehmann, A

    Gottschalk, F. & Lehmann, A. Covid-19 and Swiss Post: Volume Developments and the Economic Value of Postal Service, in the Pandemic and Beyond, 207–222 (Springer International Publishing, Cham, 2023)

  56. [64]

    & Szeidl, A

    Halpern, L., Koren, M. & Szeidl, A. Imported inputs and productivity. Am. economic review 105, 3660–3703 (2015)

  57. [65]

    & Neffke, F

    Juhász, S., Elekes, Z., Ilyés, V . & Neffke, F. Colocation of skill related suppliers–revisiting coagglomeration using firm-to-firm network data. arXiv preprint arXiv:2405.07071 (2024)

  58. [66]

    Zelbi, G., Ialongo, L. N. & Thurner, S. Systemic risk mitigation in supply chains through network rewiring (2025). 2504.12955

  59. [67]

    M., Lafond, F

    Pichler, A., Pangallo, M., del Rio-Chanona, R. M., Lafond, F. & Farmer, J. D. In and out of lockdown: Propagation of supply and demand shocks in a dynamic input-output model. arXiv preprint arXiv:2102.09608 DOI: https://doi.org/10. 48550/arXiv.2102.09608 (2021)

  60. [68]

    & Garlaschelli, D

    Mastrandrea, R., Squartini, T., Fagiolo, G. & Garlaschelli, D. Enhanced reconstruction of weighted networks from strengths and degrees. New J. Phys. 16, 043022, DOI: https://doi.org/10.1088/1367-2630/16/4/043022 (2014)

  61. [69]

    & Cimini, G

    Gabrielli, A., Mastrandrea, R., Caldarelli, G. & Cimini, G. Grand canonical ensemble of weighted networks. Phys. Rev. E 99, 030301, DOI: https://doi.org/10.1103/PhysRevE.99.030301 (2019)

  62. [70]

    & Gabrielli, A

    Cimini, G., Squartini, T., Garlaschelli, D. & Gabrielli, A. Systemic risk analysis on reconstructed economic and financial networks. Sci. Reports 5, DOI: https://doi.org/10.1038/srep15758 (2015)

  63. [71]

    & Garlaschelli, D

    Parisi, F., Squartini, T. & Garlaschelli, D. A faster horse on a safer trail: generalized inference for the efficient reconstruction of weighted networks. New J. Phys. 22, 053053, DOI: https://doi.org/10.1088/1367-2630/ab74a7 (2020)

  64. [72]

    & Newman, M

    Park, J. & Newman, M. E. Statistical mechanics of networks. Phys. Rev. E 70, 066117, DOI: https://doi.org/10.1103/ PhysRevE.70.066117 (2004)

  65. [73]

    & Munoz, M

    Caldarelli, G., Capocci, A., De Los Rios, P. & Munoz, M. A. Scale-free networks from varying vertex intrinsic fitness. Phys. Rev. Lett. 89, 258702, DOI: https://doi.org/10.1103/PhysRevLett.89.258702 (2002)

  66. [74]

    & Loffredo, M

    Garlaschelli, D. & Loffredo, M. I. Fitness-dependent topological properties of the world trade web. Phys. Rev. Lett. 93, 188701, DOI: https://doi.org/10.1103/PhysRevLett.93.188701 (2004). Acknowledgements A.M. and G.C. acknowledge financial support from the National Recovery a...

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