nep-ppm New Economics Papers
on Project, Program and Portfolio Management
Issue of 2026–01–26
seven papers chosen by
Arvi Kuura, Tartu Ülikool


  1. Modeling Policy and Resource Dynamics in the Construction Sector of Developing Countries: A System Dynamics Approach Using Sudan as a Case Study By Malik Dongla; Mohamed Khalafalla
  2. Finanzierung von Glasfaser ausbauenden Unternehmen: Wer ist wie stark von den aktuellen Herausforderungen betroffen? By Knips, Julian; Wernick, Christian; Lachmann, Menessa Ricarda
  3. Designing rebate rules in public goods provision: Axioms, limits, and comparisons By Rouault, Cyril; Zoroglu, Resul
  4. Efficiency at a Cost: How a Fiscal Rule on Disbursement Timelines Shifted Public Investment Toward Repairs By Athiphat Muthitacharoen; Phatarakorn Thongsathit; Tapanat Paiboonsin
  5. Fairing the energy transition: a policy framework for integrating stakeholder concerns in solar energy development By Rielli, L. E.; Wang, Jodi Ann
  6. Breaking the Dimensional Barrier: Dynamic Portfolio Choice with Parameter Uncertainty via Pontryagin Projection By Jeonggyu Huh; Hyeng Keun Koo
  7. When More Is Not Better: Heterogeneous Dose–Response Effects of R&D Subsidies by Firm Size By Diego Sancho-Bosch; Elena Huergo

  1. By: Malik Dongla; Mohamed Khalafalla
    Abstract: Construction industries in developing countries face systemic challenges such as chronic project delays, cost overruns, and regulatory inefficiencies. This paper presents a system dynamics (SD) modeling framework for analyzing policy and resource dynamics within the construction sector in Sudan, with broader applicability to Least Developed Countries (LDCs). The model incorporates key variables related to workforce, material supply, financing, and policy delays, and is calibrated using genetic algorithms (GAs) based on sectoral data and expert input. Simulation results across four policy scenarios indicate that regulatory reform and workforce training are the most effective levers for improving project performance. Specifically, implementing streamlined regulatory procedures reduced project delays by up to 32%, while investment in human capital decreased cost overruns by 28% over a 10-year simulation horizon. In contrast, scenarios focusing solely on material supply or financial inputs produced limited gains without corresponding policy or labor improvements. Sensitivity analysis further revealed that the system is highly responsive to macroeconomic stability and public investment flows. The study demonstrates that a hybrid SD-GA modeling approach offers a valuable decision-support tool for policymakers seeking to improve infrastructure delivery under uncertainty. Recommendations include phased regulatory reforms, targeted capacity building, and integrating modeling tools into strategic infrastructure planning in LDCs.
    Date: 2026–01
    URL: https://d.repec.org/n?u=RePEc:arx:papers:2601.02405
  2. By: Knips, Julian; Wernick, Christian; Lachmann, Menessa Ricarda
    Abstract: Der flächendeckende Glasfaserausbau in Deutschland stellt eine große finanzielle Herausforderung für die ausbauenden Unternehmen dar. Neben dem initialen Ausbau, für den in den kommenden Jahren Investitionen in zweistelliger Milliardenhöhe benötigt werden, wird auch die Nachverdichtung bestehender Netze, die größtenteils als Homes Passed ausgebaut wurden, mehrere Milliarden Euro an Investitionsmitteln erfordern. Finanzierungsmöglichkeiten und -konditionen rücken vor diesem Hintergrund zunehmend ins Zentrum der Diskussionen innerhalb der Glasfaserbranche. In einer sowohl gesamtwirtschaftlich, als auch branchenspezifisch anspruchsvollen Gesamtsituation findet sich eine Reihe von Marktteilnehmern in der Situation wieder, investive Mittel für Refinanzierungen sowie die Fortführung bestehender und die Initiierung neuer Projekte einwerben zu müssen. Die Herausforderungen, die sich aus dem gestiegenen Zinsniveau und der Zurückhaltung von Investoren im Hinblick auf Investitionen in den Glasfaserausbau ergeben, betreffen nicht alle Unternehmen bzw. Unternehmensformen in gleichem Umfang. Große börsennotierte Unternehmen, die sich insbesondere über Anleihen finanzieren, sind weniger zinssensibel und oft langfristig finanziert. Zudem finanzieren sie sich bei entsprechender Bonität im Branchenvergleich relativ günstig und können über Anleihenplatzierungen am öffentlichen Kapitalmarkt Mittel von einer Vielzahl von Investoren akquirieren. Stadtwerke und Energieversorger sind in ihren Glasfaseraktivitäten von den Problemen zwar betroffen, jedoch erscheint der Erhalt von Finanzierungen hier als nicht übermäßig kritisch. Als diversifizierte Unternehmen mit oftmals stabilen Cashflows können sie in der Regel Unternehmensfinanzierungen in Anspruch nehmen und haben im Falle von Stadtwerken einen öffentlichen Sicherheitengeber im Hintergrund. Hier steht der kapitalintensive Glasfaserausbau allerdings in einer Mittelverwendungskonkurrenz zur Finanzierung der Energie- und Wärmewende, was die Finanzierungsbedingungen perspektivisch erschweren könnte. Kritisch kann sich die Situation für investorenfinanzierte Unternehmen darstellen. Da ihr Fremdkapital meist aus Projektfinanzierungen stammt, sehen sie sich mit deutlich kürzeren Kreditlaufzeiten und höheren Zinsen als börsennotierte Unternehmen oder Stadtwerke und Versorger konfrontiert. Einige von ihnen müssen aktuell zusätzlich ihre initialen Darlehen aus den späten 2010er Jahren refinanzieren. Während das gestiegene Zinsniveau für die Glasfaserunternehmen als exogener Schock angesehen werden kann, liegt die Zurückhaltung der Fremdkapitalgeber, insbesondere im Bereich der Projektfinanzierung, nicht ausschließlich, aber in hohem Maße an der Kombination aus (zu hohen) Ausbaukosten und (zu niedrigen) Take-up-Raten bzw. Cashflows. Mutmaßlich sind die tatsächlichen Zahlen in vielen Fällen schlechter als die den Businessplänen zugrundeliegenden Annahmen. Sollten Investoren, sowohl im Eigen- wie auch im Fremdkapitalbereich, noch zurückhaltender werden, droht eine Negativspirale: Höhere Take-up-Raten in den HPAusbaugebieten, die die Finanzierung erleichtern bzw. die Zinsen reduzieren würden, bedingen Kapitalzuflüsse für Nachverdichtungs- und Vermarktungsmaßnahmen, so dass sich negative Effekte immer weiter zu verstärken drohen, wenn Unternehmen ihren Ausbau ohne zusätzliche Mittel nicht vervollständigen können, Investoren aber nur zusätzliche Mittel bereitstellen wollen, wenn sich die Geschäftszahlen der Unternehmen wieder verbessern. All dies könnte die Ausbaudynamik im deutschen Glasfasermarkt in den nächsten Jahren spürbar reduzieren, kurzfristig insbesondere im Ausbau von Wettbewerbern. Mittelfristig könnte dies durch den niedrigeren Wettbewerbsdruck aber auch eine Verlangsamung der Ausbauaktivitäten der Deutschen Telekom nach sich ziehen. Im Ergebnis besteht die Gefahr, dass die politisch definierten Breitbandziele verfehlt werden. Risikoabsorbierende staatliche Maßnahmen, wie insbesondere Programme für (Teil- )Bürgschaften oder eine Ausweitung ggf. nachrangiger Kreditmengen von Förderbanken für Glasfaserprojekte, könnten helfen, die Finanzierungssituation zu verbessern, bedürfen jedoch einer punktgenauen Ausgestaltung. Auch Maßnahmen, die darauf ausgerichtet sind, die Take-up-Raten auf FTTH-Netzen zu erhöhen und/oder die Ausbaukosten zu senken, können die Finanzierungsmöglichkeiten der im FTTH-Ausbau engagierten Unternehmen verbessern. Hierzu zählen z.B. eine klar geregelte, zeitnahe Kupfer-Glas-Migration und die Beschleunigung und Digitalisierung von Genehmigungsprozessen.
    Abstract: The nationwide rollout of fibre networks in Germany poses a major financial challenge for the companies involved. In addition to the initial rollout, which will require investments in the double-digit billion euro range in the coming years, the densification of existing networks, most of which were built as homes passed, will also require several billion euros in funds. Against this backdrop, financing options and conditions are increasingly becoming the focus of discussions within the fibre industry. In a challenging overall situation, both in terms of the economy as a whole and the industry specifically, a number of market participants find themselves in a position where they need to raise funds for refinancing, continuing existing projects and initiating new ones. The challenges arising from higher interest rates and reluctance of banks and other players to invest in fibre network expansion do not affect all companies or types of companies to the same extent. Large, publicly listed companies, which are financed primarily through bonds, are less sensitive to interest rate changes and are often financed long-term. In addition, if they have the appropriate credit rating, they can obtain financing relatively cheaply compared to other companies in the sector and can raise funds from a large number of investors by placing bonds on the capital market. Municipal utilities and energy suppliers are affected by the problems in their fibre activities, but obtaining financing does not appear to be overly critical for them. As diversified companies with often stable cash flows from other activities, they can usually take advantage of corporate financing and, in the case of municipal utilities, have a public guarantor in the background. However, capital-intensive fibre rollout is in competition with the financing of the energy and heating transition to renewable sources, which could make financing conditions more difficult in the future. The situation can be critical for investor-financed companies. Since their debt usually comes from project financing, they are faced with significantly shorter loan terms and higher interest rates than listed companies or municipal utilities and suppliers. Some of them currently have to refinance their initial loans from the late 2010s. While the rise in interest rates can be seen as an exogenous shock for fibre companies, the reluctance of lenders, particularly for companies in need of project financing, is not exclusively, but to a large extent, due to the combination of (excessively high) rollout/build costs and (excessively low) take-up rates or cash flows. Presumably, the actual figures are worse in many cases than the assumptions underlying the business plans. If investors, both in the equity and debt space, become even more cautious, there is a risk of a negative spiral: higher take-up rates in the homes passed expansion areas, which would facilitate financing and reduce interest rates, require capital inflows for densification and marketing measures. Therefore negative effects threaten to intensify further if companies are unable to complete their expansion without additional funds, but investors are only willing to provide additional funds if the companies' business figures improve. All of this could significantly reduce the pace of rollout in the German fibre market in the coming years, particularly in the short term with regard to expansion by competitors of the incumbent. In the medium term, however, this could also lead to a slowdown in Deutsche Telekom's expansion activities due to lower competitive pressure. As a result, there is a risk that the politically defined broadband goals will not be met. Risk-absorbing government measures, such as programmes for (partial) guarantees or an expansion of subordinated credit volumes from development banks for fibre projects, could help to improve the financing situation, but would need to be designed with precision. Measures aimed at increasing take-up rates on FTTH networks and/or reducing expansion costs can also improve the financing options for companies involved in FTTH rollout. These include, for example, a clearly regulated, timely copper-to-fibre migration and the acceleration and digitisation of approval processes.
    Keywords: Glasfaserkommunikation, Deutschland
    Date: 2025
    URL: https://d.repec.org/n?u=RePEc:zbw:wikdps:334505
  3. By: Rouault, Cyril; Zoroglu, Resul
    Abstract: This paper examines rebate rules in the context of public goods provision. These rules aim to redistribute the surplus when total contributions exceed the cost of the project. Using an axiomatic approach, we establish impossibility results that highlight the inherent tensions between fairness, participation incentives, and contribution incentives. We then propose and characterize the Proportional Rebate with Threshold rule, which identifies a coherent trade-off across these objectives.
    Keywords: Public goods provision, Crowdfunding, Axioms, Rebates, Fairness
    JEL: D63 D71 D82 G32
    Date: 2025
    URL: https://d.repec.org/n?u=RePEc:zbw:kitwps:335020
  4. By: Athiphat Muthitacharoen; Phatarakorn Thongsathit; Tapanat Paiboonsin
    Abstract: This paper examines how an efficiency-oriented fiscal rule influences the composition of public investment. We study Thailand’s 2021 fiscal rule reform limiting the disbursement period for investment budgets to one year after initial approval, replacing a previously unrestricted timeline. We apply seeded LDA model to classify over 360, 000 Thailanguage government projects and to estimate the probability that each project reflects repair activity. We then implement a difference-in-differences framework. Our identification exploits variation in departments’ pre-policy reliance on construction projects, which proxy exposure to tighter disbursement constraints. We find that departments more exposed to the reform significantly increased their reliance on repairoriented projects, which are typically simpler and faster to execute. This adjustment emerges gradually, is more pronounced among larger departments, and coincides with higher post-reform disbursement rates, indicating that the policy achieved its primary objective of accelerating budget execution. At the same time, the results suggest a tradeoff: efficiency-oriented fiscal rules can alter agencies’ incentives in ways that shift investment portfolios toward projects that are easier to implement under tighter timelines. Overall, the study highlights how fiscal rule design can shape not only the pace but also the composition of public investment.
    Keywords: Fiscal rules; Public investment composition; Budget execution; Administrative behavior; Impact evaluation
    JEL: H54 H61 C55
    Date: 2026–01
    URL: https://d.repec.org/n?u=RePEc:pui:dpaper:246
  5. By: Rielli, L. E.; Wang, Jodi Ann
    Abstract: Ensuring that the energy transition actively accounts for stakeholders' concerns is critical to both addressing and redressing (in)justices. From an energy justice perspective, key aspects – including distributive, procedural, recognitional, and restorative justice – must be duly inscribed across the lifecycles of new renewable energy infrastructures. This article aims to identify the salient stakeholder concerns and propose corresponding policy actions that embed justice principles in the energy transition. It particularly emphasizes on the implications for affected stakeholders groups, namely workers, suppliers, communities, and consumers. Drawing on evidence from ethnographic field observations and semi-structured interviews (n = 47) in solar photovoltaic energy projects in Brazil and Portugal, this Perspective article proposes a framework of structural and practical policy actions that centre the affected stakeholders' concerns, which can be adapted across global geographies. This work contributes to the just energy transitions global agenda by providing practical recommendations for integrating justice into energy policies.
    Keywords: energy justice; energy transition; policy; Policy; Energy justice; Energy transition
    JEL: R14 J01
    Date: 2026–01–31
    URL: https://d.repec.org/n?u=RePEc:ehl:lserod:130918
  6. By: Jeonggyu Huh; Hyeng Keun Koo
    Abstract: We study continuous-time CRRA portfolio choice in diffusion markets with uncertain estimated coefficients. Nature draws a latent parameter from a given distribution and keeps it fixed; the investor cannot observe this parameter and must commit to a parameter-blind policy maximizing an ex-ante objective. We treat the uncertainty distribution as an inference-agnostic sampling input. We develop a simulation-only two-stage solver. Stage 1 extends Pontryagin-Guided Direct Policy Optimization (PG-DPO) by sampling parameters internally and computing gradients via backpropagation through time. Stage 2 performs an aggregated Pontryagin projection: it aggregates costates across the parameter distribution to enforce a deployable stationarity condition, yielding a structured correction amortized via interactive distillation. We prove a uniform conditional BPTT-PMP correspondence and a residual-based policy-gap bound with explicit error terms. Experiments on high-dimensional Gaussian drift and factor-driven benchmarks show that projection stabilizes learning and accurately recovers analytic references, while a model-free PPO baseline remains far from the targets.
    Date: 2026–01
    URL: https://d.repec.org/n?u=RePEc:arx:papers:2601.03175
  7. By: Diego Sancho-Bosch (Department of Economic Analysis, Universidad Complutense de Madrid (Spain)); Elena Huergo (ICAE – Department of Economic Analysis, Universidad Complutense de Madrid (Spain))
    Abstract: This paper examines how the level of public R&D subsidies and firm size jointly influence firms’ net R&D investment. Using data on Spanish manufacturing firms from 2008 to 2018, we estimate parametric and non-parametric dose–response functions after applying entropy weighting to balance covariate distributions across treatment levels. The results reveal an inverted U-shaped relationship between subsidy intensity and net R&D expenditure for small, medium-sized, and large firms, but not for very large firms, which display a negative linear pattern. We also find substantial heterogeneity in subsidy effects within both the SME and large-firm categories, and show that the public funding share of R&D expenditure at which the positive impact of subsidies peaks declines markedly with firm size. These findings suggest that support schemes should implement progressively lower maximum subsidy rates, rather than relying on only two distinct caps for SMEs and larger firms. Overall, the results underscore firm size as a critical determinant of innovation policy effectiveness and provide practical guidance for optimizing subsidy design.
    Keywords: R&D support, policy evaluation, dose-response, entropy balancing.
    JEL: L24 L25 O32 R11
    Date: 2025
    URL: https://d.repec.org/n?u=RePEc:ucm:doicae:2509

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