At the level of Aggregation, pathways describe how system-level states evolve once individual choices and interactions have been compressed into aggregate variables. Unlike Choice and Interaction, aggregation pathways do not organize decision-making or strategic coordination. They organize construction, transmission, and reorganization of aggregates under accounting, feasibility, and intertemporal constraints.
The defining feature of aggregation pathways is that they operate over assembled quantities rather than individual entities. Pathway structure at this level is therefore dominated by processes that build aggregates from components, carry constraints and shocks across time or sectors, and accommodate qualitative shifts in system-wide regimes. Selection and semantic transformation do not survive as admissible pathway forms at this layer; aggregation does not choose among alternatives or convert state meaning, it constrains and composes.
Pathway status at the macro level reflects this structural reality. Assembly, propagation, and regime transition form the pathway spine of aggregation, because without them there is no coherent system-level description. Other archetypes appear only as secondary refinements or are structurally inadmissible given the invariants of macroeconomic accounting. The sections that follow describe how each pathway archetype functions—or fails to function—within aggregation, clarifying what kinds of causal organization are possible once economic activity is represented at the system scale.
SAT – Structure – Pathways – Archetypes (the 7) – Aggregation & Dynamics (Macroeconomic Systems)
| Archetype | Status | Structural Role |
|---|---|---|
| Propagation | Primary | Transmits shocks, flows, and constraints across time and sectors. |
| Transformation | Absent | Semantic state conversion does not survive aggregation as a law-level pathway. |
| Selection | Absent | Aggregation does not eliminate states; it constrains them. |
| Iteration | Secondary | Supports time-indexed accumulation and updating. |
| Feedback | Secondary | Enables stabilization via constraint propagation. |
| Assembly | Primary | Constructs aggregate variables from components. |
| Regime Transition | Primary | Captures structural breaks and macro regime shifts. |
Propagation
In Aggregation, propagation organizes how aggregate state changes are transmitted across time, sectors, or accounting boundaries without altering their semantic type. What propagates at this level are not individual actions or strategic signals, but system-level quantities and constraints—such as balances, gaps, or shocks—that remain invariant in meaning as they move through the macroeconomic system.
Structurally, propagation in aggregation consists of sequential linkage of aggregate mechanisms in which the output of one accounting or updating operation becomes the input to the next. This linkage ensures continuity of system-wide influence: a change introduced at one point in the aggregate structure remains causally relevant elsewhere. The pathway preserves the identity of the aggregate variable while allowing its magnitude or timing to evolve.
Propagation is primary at the macro level because aggregation without transmission collapses into static snapshots. Without propagation pathways, there is no way for aggregate conditions to carry forward, no mechanism for intertemporal consistency, and no coherent description of system evolution. In composite macro pathways, propagation serves as the connective structure through which assembly, feedback, and regime transitions exert system-wide effect, but its defining role remains constant: to carry aggregate state change through the macroeconomic architecture without redefining its meaning.
Transformation
Transformation is structurally inadmissible as a core pathway archetype at the level of aggregation. Aggregation operates over variables whose semantic meaning is fixed by accounting definitions, balance relations, and system boundaries. While the values of aggregate variables may change, their type and representational role do not. Any process that converts aggregate states into different kinds of states violates the invariants that make aggregation coherent.
Introducing transformation at this level would imply that aggregate quantities change their semantic interpretation—turning one category of state into another—which collapses the distinction between accounting construction and model-specific reinterpretation. When apparent transformations are observed in macro descriptions, they reflect either changes in classification conventions, shifts in regime definitions, or transitions to a different analytic layer, not lawful aggregation pathways.
For this reason, transformation does not function as an admissible pathway archetype within aggregation. Processes that resemble transformation at the macro scale must be analyzed either as assembly under new definitions, regime transitions, or as mechanisms operating at lower layers prior to aggregation.
Selection
Selection is structurally inadmissible as a pathway archetype at the level of aggregation. Aggregation does not operate by eliminating admissible states or choosing among alternatives; it operates by composing, constraining, and accounting for all states simultaneously. Aggregate descriptions preserve completeness rather than prune possibility.
At this layer, removing states would violate core invariants of aggregation—specifically balance, closure, and stock–flow consistency. Aggregate systems do not “discard” outcomes that fail criteria; instead, constraints are enforced through identities and feasibility relations that apply to the entire state space at once. What may appear as selection at the macro scale is either the result of selection mechanisms at lower layers prior to aggregation, or the effect of regime transition, where the admissible state space itself is redefined.
Accordingly, selection cannot function as a lawful pathway within aggregation. Any analytic move that introduces elimination or retention among aggregate states indicates a shift away from aggregation toward modeling assumptions, institutional filtering, or lower-level dynamics.
Iteration
In Aggregation, iteration organizes how aggregate states are updated repeatedly over indexed steps, typically across time. Unlike interaction-level iteration, which reflects strategic adjustment, iteration at the macro level is procedural rather than adaptive. It applies a stable update structure to evolving aggregate variables in order to maintain intertemporal coherence.
Structurally, iteration in aggregation consists of repeated execution of the same aggregate updating mechanisms—such as accumulation or balance updating—under fixed accounting rules. Each step takes the aggregate state from the previous step and produces a new aggregate state, without altering the governing laws, invariants, or semantic interpretation of variables. The pathway advances through successive updates rather than through conversion or elimination.
Iteration is secondary at the aggregation level because it is not sufficient on its own to define macroeconomic structure. Aggregation can be statically coherent without iteration, but cannot be dynamically coherent over time without it. Iteration therefore serves as a refinement that enables time-indexed evolution, supporting propagation and assembly while remaining subordinate to the balance and regime-defining structures that govern aggregation as a whole.
Feedback
In Aggregation, feedback organizes how aggregate outcomes condition subsequent aggregate constraints or updating rules without altering the semantic identity of aggregate variables. Unlike interaction-level feedback, which reflects strategic response, macro-level feedback is structural and constraint-mediated. It operates through the re-entry of aggregate state values into the conditions governing future system evolution.
Structurally, feedback in aggregation consists of closed-loop linkage between aggregate states and aggregate updating mechanisms. Outputs from one stage—such as accumulated balances or system-wide conditions—modify the parameters or constraints under which subsequent aggregation steps proceed. The governing rules themselves remain fixed; what changes is how tightly or loosely those rules bind given the evolving aggregate state.
Feedback is secondary at the aggregation level because it refines how the system responds over time rather than defining aggregation itself. Aggregation can exist without feedback as a static accounting structure, but feedback becomes necessary once the system is extended temporally and allowed to react to its own accumulated conditions. In composite macro pathways, feedback modulates propagation and iteration, supporting stabilization or amplification while remaining subordinate to the balance and regime structures that anchor aggregation.
Assembly
In Aggregation, assembly organizes how system-level states are constructed from component quantities. This pathway archetype specifies the causal architecture by which individual or sectoral variables are combined into coherent aggregates while preserving accounting meaning and closure. What defines assembly at this level is not mere accumulation, but the formation of higher-order variables whose interpretation depends on structured combination rather than on any single component.
Structurally, assembly in aggregation consists of convergent execution of aggregation mechanisms. Multiple inputs—originating from distinct entities, sectors, or accounts—are brought together under fixed aggregation rules to produce system-level quantities. These rules define how components relate, how boundaries are drawn, and how totals are formed, ensuring that the resulting aggregate states are internally consistent and semantically stable.
Assembly is primary at the aggregation level because aggregation without construction is impossible. Without assembly pathways, there are no macroeconomic variables—only unconnected micro-level data. Assembly therefore forms the backbone of macroeconomic representation, enabling all other macro pathways to operate. Propagation, iteration, feedback, and regime transition act on assembled states, but they cannot replace the foundational role of assembly in creating them.
Regime Transition
In Aggregation, regime transition organizes how the governing structure of the macroeconomic system itself changes. Unlike propagation, iteration, or feedback—which operate within a fixed set of accounting definitions and constraints—regime transition captures moments where those definitions, constraints, or admissible dynamics are redefined. What changes is not merely the value of aggregate variables, but the structural context in which those variables are interpreted and constrained.
Structurally, regime transition consists of a threshold-mediated reorganization of aggregation pathways. Accumulated aggregate states reach conditions under which previously stable relations no longer hold, triggering a shift to a new regime with different effective constraints, balances, or dominant pathways. Once the transition occurs, assembly, propagation, and feedback continue to operate, but under a different structural configuration.
Regime transition is primary at the aggregation level because macroeconomic systems cannot be coherently described as evolving smoothly under a single, unchanging structure. Without regime transition pathways, aggregation would falsely assume continuity across periods where accounting relations, feasibility constraints, or system-wide behaviors fundamentally change. Regime transition therefore defines the boundaries between distinct macroeconomic phases, marking where one aggregate structure ends and another begins.