Politics, Inequality, and the Robustness of Shared Infrastructure Systems

TL;DR

The paper develops a dynamic political-economic model of shared infrastructure that couples $I^s$, $I^p$, labor $l$, and tax policy $\tau$ under inequality and political competition. It introduces DirectAgg and PolComp variants, augmented with cold/hot cognition and redistribution mechanisms (user fees vs total income taxing), to study robustness under capacity shocks and elite investment opportunities. Key findings reveal that private-inequality reduces robustness under user fees, while income taxation can enhance resilience if elite capture is mitigated; robustness exhibits a parabolic dependence on election-cycle length $T_e$, and higher ideological sensitivity $\sigma_R$ tends to reduce robustness. These results underscore the importance of institutional design and political processes, not just engineering fixes, for maintaining equitable and reliable infrastructure in the face of future shocks.

Abstract

Our infrastructure systems enable our well-being by allowing us to move, store, and transform materials and information given considerable social and environmental variation. Critically, this ability is shaped by the degree to which society invests in infrastructure, a fundamentally political question in large public systems. There, infrastructure providers are distinguished from users through political processes, such as elections, and there is considerable heterogeneity among users. Previous political economic models have not taken into account (i) dynamic infrastructures, (ii) dynamic user preferences, and (iii) alternatives to rational actor theory. Meanwhile, engineering often neglects politics. We address these gaps with a general dynamic model of shared infrastructure systems that incorporates theories from political economy, social-ecological systems, and political psychology. We use the model to develop propositions on how multiple characteristics of the political process impact the robustness of shared infrastructure systems to capacity shocks and unequal opportunity for private infrastructure investment. Under user fees, inequality decreases robustness, but taxing private infrastructure use can increase robustness if non-elites have equal political influence. Election cycle periods have a nonlinear effect where increasing them increases robustness up to a point but decreases robustness beyond that point. Further, there is a negative relationship between the ideological sensitivity of candidates and robustness. Overall, the biases of voters and candidates (whether they favor tax increases or decreases) mediate these political-economic effects on robustness because biases may or may not match the reality of system needs (whether system recovery requires tax increases).

Figures (10)

• Figure 1: Summary of model components using the layout defined by the Coupled Infrastructure Systems Framework Muneepeerakul2017Muneepeerakul2020. Arrows indicate flows of material and information and thought bubbles indicate dynamic decisions made by users and shared infrastructure providers.
• Figure 2: Political dimensions considered in model development and analysis. We begin (first row) with three central assumptions that add complexity to the infrastructure system: (i) inequality, (ii) limits to rationality, and (iii) discrete and cyclic political change. We then (second row) consider the structural features of the model that implement the assumptions within the model's dynamics and characterize their effect on infrastructure politics: (i) redistributive capacity, (ii) solution biases, and (iii) response capacity. In the last two rows, we explain how we operationalized each political dimension in the DirectAgg and the PolComp models, respectively.
• Figure 3: There are four post-shock states for the system: Full Shared (full shared infrastructure capacity, no private capacity), Elites Abandon (no shared capacity, full private capacity for elites), Distinct Societies (full shared capacity, full private capacity for elites), and Collapse (no infrastructure capacity). We plot four example trajectories of the post-shock states from the same initial shock of a 50% reduction in shared infrastructure capacity that differ by whether there is a user fee or total income tax in place and the private infrastructure investment opportunity for elites. The trajectories that lead to Distinct Societies and Full Shared states provide examples of the limit cycle behavior created by overshoots in the competitive electoral cycle.
• Figure 4: The NoPolitics and DirectAgg models differ in their safe operating spaces under user fee (A-D) and total income taxing mechanisms (E-H). Each panel contains the robustness results (whether shared infrastructure was preserved) for a given political model (\ref{['fig:typetree']}) over the two-dimensional shock space (shared infrastructure capacity and elite private opportunity). We do not plot results from the hot cognition and elite control (EC-Hot) model because the shared infrastructure system always collapses. Cold cognition, user fee models have a smaller region of shared infrastructure preservation (lower robustness) at high elite opportunity (B-C). Total income taxing prevents this effect when there is median voter influence (F), but under elite control (G), elites remove the tax when they abandon the shared system. Under hot cognition and median voter influence (D, H), system recovery is only limited by available taxable income, which is compromised at high shared infrastructure shock levels.
• Figure 5: The two dimensions of redistributive capacity, resources and power (Figure \ref{['fig:typetree']}), have an interactive effect on the robustness of shared infrastructure to capacity and elite opportunity shocks. We present the results from the four-dimensional sensitivity analysis ($T_e$, $\sigma_R$, $\Delta^{I_s}$, $\Delta^{\mu^p_1}$) conducted on each political model (\ref{['fig:typetree']}) as a projection onto the shock space ($\Delta^{I_s}$ vs. $\Delta^{\mu^p_1}$) in A & B, showing the average change to robustness by having equal influence for each shock combination. In C, we plot the total average change over the entire sensitivity analysis to robustness, as well as the relative frequency of each equilibrium state due to having equal voter influence. When under a user fee model (A), equal influence decreases robustness when there is high elite opportunity ($\Delta^{\mu^p_1}$). However, total income taxing (B) benefits from equal political influence. This effect occurs for both initial incumbents (C) but is less strong for a tax-repulsed initial incumbent.