ASSEMBLY-WP-0018-T01: dematerialization vs. Eurostat resource productivity; operator corrected; decoupling depends on phi_r (EU fit 0.66: none; DE 0.15: holds), BR-011; E5 wired

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 14913@bnt-lap001
Assistant-Session: add7ef69-b901-4756-9a67-34cf1125d96f

AGENTS.md

@@ -43,6 +43,7 @@ cd simulations/gadm02 && python3 -B nonrival.py   # GADM-0.5-dev rival vs. non-r
 cd simulations/gadm02 && python3 -B eco_classes.py   # GADM-0.5-dev ecological resource classes
 cd simulations/gadm02 && python3 -B selection.py   # GADM-0.5-dev endogenous selection weights
 cd simulations/gadm02 && python3 -B demand.py   # GADM-0.5-dev two-good demand split (dematerialization)
+cd simulations/gadm02 && python3 -B dematerialization.py   # material intensity vs. Eurostat resource productivity; phi_r fit
 cd simulations/gadm02 && python3 -B matching.py && python3 -B matching.py --imm   # model matching; IMM flip-detection acceptance test (~6 min)
 ```
 

checkpoints/IndicatorCatalog.md

@@ -259,3 +259,13 @@ values.
 CB6 tells whether Argentina moves toward the export path that would let it
 out-grow the EU on output (`models/CrossBorder.md` § 7): from about 4.5 % of
 GDP upward.
+
+## Dematerialization indicator (ASSEMBLY-WP-0018-T01)
+
+| ID | Indicator | Jurisdiction | Source | Access | Cadence |
+|---|---|---|---|---|---|
+| E5 | Resource productivity: GDP per kg of domestic material consumption (chain-linked 2015 EUR) | EU, DE | Eurostat `env_ac_rp` (wired in `sources.json`, kind full) | api | a |
+
+E5 constrains the rival share of organism output φ_r through the
+material-intensity trend (`models/GADM-0.5.md` § 5). Post-2024 values are the
+first that reflect generative-AI adoption.

checkpoints/sources.json

@@ -30,6 +30,7 @@
     {"id": "E1-DE", "indicator": "E1", "kind": "full", "jurisdiction": "DE", "label": "CO2 emissions excluding LULUCF", "adapter": "http_json", "url": "https://api.worldbank.org/v2/country/DEU/indicator/EN.GHG.CO2.MT.CE.AR5?format=json&mrnev=1", "path": "1.0.value", "period_path": "1.0.date", "unit": "Mt CO2e", "source": "World Bank WDI (EN.GHG.CO2.MT.CE.AR5)"},
     {"id": "E1-AR", "indicator": "E1", "kind": "full", "jurisdiction": "AR", "label": "CO2 emissions excluding LULUCF", "adapter": "http_json", "url": "https://api.worldbank.org/v2/country/ARG/indicator/EN.GHG.CO2.MT.CE.AR5?format=json&mrnev=1", "path": "1.0.value", "period_path": "1.0.date", "unit": "Mt CO2e", "source": "World Bank WDI (EN.GHG.CO2.MT.CE.AR5)"},
     {"id": "E2-EU-DE", "indicator": "E2", "kind": "full", "jurisdiction": "EU, DE", "label": "Domestic material consumption per capita", "adapter": "eurostat", "dataset": "env_ac_mfa", "filters": {"geo": ["EU27_2020", "DE"], "material": "TOTAL", "indic_env": "DMC", "unit": "T_HAB"}, "split_by": ["geo"], "last": 1},
-    {"id": "E4-EU-DE", "indicator": "E4", "kind": "full", "jurisdiction": "EU, DE", "label": "Circular material use rate", "adapter": "eurostat", "dataset": "env_ac_cur", "filters": {"geo": ["EU27_2020", "DE"], "unit": "PC"}, "split_by": ["geo"], "last": 1}
+    {"id": "E4-EU-DE", "indicator": "E4", "kind": "full", "jurisdiction": "EU, DE", "label": "Circular material use rate", "adapter": "eurostat", "dataset": "env_ac_cur", "filters": {"geo": ["EU27_2020", "DE"], "unit": "PC"}, "split_by": ["geo"], "last": 1},
+    {"id": "E5-EU-DE", "indicator": "E5", "kind": "full", "jurisdiction": "EU, DE", "label": "Resource productivity (GDP per kg of domestic material consumption, chain-linked 2015 EUR)", "adapter": "eurostat", "dataset": "env_ac_rp", "filters": {"geo": ["EU27_2020", "DE"], "unit": "EUR_KG_CLV15"}, "split_by": ["geo"], "last": 1}
   ]
 }

models/GADM-0.5.md

@@ -181,10 +181,8 @@ A *decoupled decade* has VFAC rising, physical throughput falling and K_Ω not
 falling, which excludes the artifact of § 1.3. Baseline: decoupled decades
 0–0.09, and no sinks breach with or without the split.
 
-Calibration check: throughput per unit of output falls by 0.1–0.5 % per year
+Calibration check: see § 5. (A first comparison here used total throughput
-in the first decade (split cases included). Observed EU dematerialization is
+per output, which is the wrong operator.)
-about 1.6 % per year (resource productivity, 2000–2022). The observed trend
-includes efficiency gains that GADM does not model.
 
 ### 4.3 Readings
 
@@ -201,8 +199,56 @@ includes efficiency gains that GADM does not model.
    split moves it 15–50 years later. The strong split removes it within the
    horizon at every anchor. Together with low-carbon electricity (§ 2.3), this
    is the second lever on the regime's ecological cost.
-4. **The readings are conservative against data.** Observed
+4. ~~The readings are conservative against data.~~ **Corrected in § 5:**
-   dematerialization (−1.6 % per year) is three to sixteen times the modeled
+   that comparison used total throughput per output, which includes compute
-   intensity decline, because GADM has no autonomous efficiency trend.
+   energy. On the right operator (material draw per output), the model already
-   Calibrating ε, λ and an efficiency trend to the observed series is the next
+   dematerializes as fast as observed. The decoupling reading then depends on
-   step (ASSEMBLY-WP-0018).
+   the rival share φ_r, and the EU data do not support it.
+
+## 5. Dematerialization against data (ASSEMBLY-WP-0018-T01)
+
+**Data:** Eurostat resource productivity (`env_ac_rp`, GDP per kg of
+domestic material consumption, chain-linked 2015 EUR). It rose 1.85 % per
+year in the EU and 2.73 % per year in Germany over 2010–2024. Material
+intensity fell at the same rates.
+
+**Operator:** the material draw per unit of output in the first decade from
+the calibrated start. Total throughput per output is the wrong operator,
+because it includes compute energy, which grows with adoption.
+
+| Jurisdiction | Observed | Model, no split (φ_r 0.2) | Model, split ε 2 (φ_r 0.2) | φ_r that reproduces the data (split ε 2) |
+|---|---|---|---|---|
+| EU | −1.85 %/y | −2.45 %/y | −2.89 %/y | **0.66** |
+| DE | −2.73 %/y | −2.26 %/y | −2.64 %/y | **0.15** |
+
+No efficiency trend is needed: non-rival organism output that needs no
+materials already makes output grow faster than material use. The data
+constrain the rival share of organism output φ_r, given the demand split. The
+two parameters are not separately identified by one series.
+
+Generative regime, demand split at its default (`dematerialization.py`,
+`results/dematerialization.md`):
+
+| φ_r | decoupled decades B1 / B2 / B3 / B4 | sinks breach B2 / B3 / B4, no split → split |
+|---|---|---|
+| 0.15 (fits DE) | 0 / 0.55 / 0.72 / 0.24 | 49 → none / 37 → 67 / 29 → 41 |
+| 0.20 (prior) | 0 / 0.45 / 0.71 / 0.22 | 49 → 98 / 37 → 61 / 29 → 40 |
+| 0.66 (fits EU) | 0 / 0 / 0 / 0.02 | 49 → 58 / 37 → 43 / 29 → 33 |
+
+Readings:
+
+1. **The decoupling reading of § 4 depends on the non-rival share of organism
+   output.** It holds when organism output is mostly non-rival (φ_r ≤ 0.2, the
+   task-data prior and the German fit). It disappears when it is mostly rival
+   (φ_r 0.66, the EU fit). Recorded as BR-011.
+2. **The fit is weakly identified.** The 2010–2024 dematerialization
+   happened mostly before generative AI, while the model attributes it to
+   organism output and demand composition. Structural change, the energy
+   transition and offshoring of material-intensive production are not in the
+   model. The first decisive data are post-2024 values of E5, now wired into
+   the full checkpoint.
+3. **Practical reading:** whether AI-era growth decouples welfare from
+   ecological load is an empirical question about *what organisms produce*.
+   Information services (non-rival) support decoupling. Automation of physical
+   production (rival) does not. The checkpoints should watch φ_r through L4
+   (task shares) and E5 (material intensity) together.

research/BreakRegister.md

@@ -23,3 +23,4 @@ that part of the band.
 | BR-008 | 2026-10-13 (WP-0011-T05) | Which levers bound domination (BR-007 follow-up) | closed model: host rights levers → coupled model: only host access rules on foreign operators and the home's levers reach the foreign-run channels | measured channels (Pd, Pmem, Plin, Pi) are operated from the US for EU and AR hosts | **structural, implemented:** cross-border coupling (`world.py`); observed DMA effect on search ≈ 0 (at most a 0.006/yr) | update 2026-10-13 (WP-0016-T01): a host lineage access rule does reach imported-lineage concentration (EU Plin 0.91 → 0.19 at a 0.15); portability needs the domestic lineage market's concentration (CB3) |
 | BR-009 | 2026-10-13 (WP-0012) | Sentiment dynamics of the legitimacy loop | Σ relaxes toward 0.5 + gain × Δ(perceived benefit), so from the measured US Σ 0.285 it rises → measured US sentiment fell 2021–2026 (0.405 → 0.285) while adoption grew fast | the neutral reference 0.5 is an assumption; US adoption also shows no braking by low sentiment (all loop-on candidates fail the US match) | **resolved 2026-10-13 (WP-0017-T01):** parameter `sig_ref`; calibrated runs anchor Σ at its measured level, and adoption and legislation respond to changes relative to it. Default (None = 0.5) keeps earlier results. R1–R4 and H1/H2 verdicts unchanged; the matching loop weights become ≈ 0.5 | resolved; `sig_adopt` not yet identified |
 | BR-010 | 2026-10-13 (WP-0007-T01) | Non-rival growth decouples welfare from throughput (core hypothesis, GADM-0.1 § 14) | output split rival / non-rival (GADM-0.5-dev): no genuine decoupling in any anchor; the generative regime's ecological cost unchanged | GADM has no demand composition: non-rival output adds to, but never replaces, rival consumption | **resolved 2026-10-13 (WP-0007-T04):** two-good demand split; the generative regime decouples in 45–71 % of decades at B2–B3, and its sinks breach moves 15–50 years later; band-dependent (none at B1) | resolved; calibration to observed dematerialization open (WP-0018) |
+| BR-011 | 2026-10-13 (WP-0018-T01) | Genuine decoupling in the generative regime (BR-010 resolution) | holds for φ_r ≤ 0.2 (task-data prior; DE dematerialization fit 0.15) → disappears at φ_r 0.66 (EU dematerialization fit) | the reading depends on the rival share of organism output, which the 2010–2024 data constrain only weakly (pre-generative-AI) | none structural; empirical: watch L4 task shares and E5 material intensity after 2024 | open |

simulations/gadm02/dematerialization.py

@@ -0,0 +1,106 @@
+"""Calibrate dematerialization to observed resource productivity (ASSEMBLY-WP-0018-T01).
+
+Observed: EU resource productivity (GDP per kg of domestic material consumption, chain-linked
+2015 EUR; Eurostat env_ac_rp) rose 1.85 %/year in 2010-2024 (DE 2.73 %/year). Model operator:
+the material draw per unit of output (rows "mat" / Y*) in the first decade. The model reproduces
+the trend without an efficiency trend; the data constrain the rival share of organism output
+phi_r (with the demand split at its default). The T04 readings are re-run at the fitted phi_r.
+
+Usage: python3 -B simulations/gadm02/dematerialization.py
+"""
+
+from __future__ import annotations
+
+import json
+import sys
+from pathlib import Path
+
+sys.dont_write_bytecode = True
+
+import band_probe as bp  # noqa: E402
+import demand as dm  # noqa: E402
+import gadm05 as g5  # noqa: E402
+import grounding as gr  # noqa: E402
+from scenarios import load_all  # noqa: E402
+
+HERE = Path(__file__).resolve().parent
+OUT = HERE / "results"
+OBS = {"EU": -0.0185, "DE": -0.0273}       # yearly change of material intensity, 2010-2024
+SPLIT = {"dm_lam": 0.05, "dm_eps": 2.0}
+
+
+def cal_start(jur: str) -> tuple[dict, dict]:
+    st = json.loads((OUT / "calibrated_starts.json").read_text())[jur]
+    return {k: v for k, v in st["params"].items() if k in g5.PARAMS}, dict(st["init"])
+
+
+def trend(p: dict, s: dict, eff: float, years: int = 10) -> float:
+    """Yearly change of material draw per unit of output over the first `years`."""
+    rows = g5.simulate_eco(p, s, eco={"rm": "rest"}, demand={**SPLIT, "eff": eff}, T=years, record_every=10)
+    a, b = rows[0], rows[-1]
+    return ((b["mat"] / b["Ystar"]) / (a["mat"] / a["Ystar"])) ** (1 / years) - 1
+
+
+def mat_trend(p: dict, s: dict, phi: float, demand: dict, years: int = 10) -> float:
+    rows = g5.simulate_eco({**p, "phi_r": phi}, s, eco={"rm": "rest"}, demand=demand, T=years, record_every=10)
+    a, b = rows[0], rows[-1]
+    return ((b["mat"] / b["Ystar"]) / (a["mat"] / a["Ystar"])) ** (1 / years) - 1
+
+
+def fit_phi(p: dict, s: dict, target: float) -> float:
+    """Rival share of organism output phi_r that reproduces the observed material-intensity trend."""
+    lo, hi = 0.0, 1.0
+    for _ in range(25):
+        mid = 0.5 * (lo + hi)
+        lo, hi = (mid, hi) if mat_trend(p, s, mid, SPLIT) < target else (lo, mid)
+    return 0.5 * (lo + hi)
+
+
+def main() -> None:
+    OUT.mkdir(exist_ok=True)
+    lines = ["# GADM-0.5-dev: dematerialization against observed resource productivity", "",
+             "Generated by `simulations/gadm02/dematerialization.py` (ASSEMBLY-WP-0018-T01). Observed: material",
+             "intensity (inverse of Eurostat resource productivity, env_ac_rp, chain-linked 2015 EUR per kg DMC),",
+             "2010-2024. Model operator: material draw per unit of output in the first decade from the calibrated",
+             "start (Calibration v0.5) with ecological classes. Total throughput per output is the wrong operator",
+             "(it includes compute energy).", "",
+             "## Fit", "",
+             "| Jurisdiction | observed | model, no split (φ 0.2) | model, split ε 2 (φ 0.2) | φ_r reproducing the observation (split ε 2) |",
+             "|---|---|---|---|---|"]
+    phis = {}
+    for jur, target in OBS.items():
+        p, s = cal_start(jur)
+        phis[jur] = fit_phi(p, s, target)
+        lines.append(f"| {jur} | {100 * target:+.2f} %/y | {100 * mat_trend(p, s, 0.2, {'dm_lam': 0.0}):+.2f} %/y | "
+                     f"{100 * mat_trend(p, s, 0.2, SPLIT):+.2f} %/y | {phis[jur]:.2f} |")
+    scs = load_all()
+    var = {a: gr.variant(gr.BAND[a]) for a in dm.ANCHORS}
+    lines += ["", "## T04 readings at the prior and at the EU-fitted φ_r (generative regime, material replenishment at rest)",
+              "", "| φ_r | Anchor | decoupled decades no split → split | sinks breach no split → split | VFAC no split → split |",
+              "|---|---|---|---|---|"]
+    res = {}
+    for phi in (0.2, round(phis["DE"], 2), round(phis["EU"], 2)):
+        for a in dm.ANCHORS:
+            out = {}
+            for cn, cd in (("none", {"dm_lam": 0.0}), ("split", SPLIT)):
+                rows = g5.simulate_eco({**scs["generative_regime"]["params"], **var[a][0], "phi_r": phi},
+                                       {**scs["generative_regime"]["init"], **var[a][1]}, eco={"rm": "rest"}, demand=cd)
+                out[cn] = {"dec": dm.decoupled_windows(rows), "V": rows[-1]["VFAC"],
+                           "sink": next((r["t"] for r in rows if r["Es"] < g5.ECO_PARAMS["eco_floor"]), None)}
+            res[(phi, a)] = out
+            fs = lambda x: f"t {x:.0f}" if x is not None else "none"  # noqa: E731
+            lines.append(f"| {phi} | {a} | {out['none']['dec']:.2f} → {out['split']['dec']:.2f} | "
+                         f"{fs(out['none']['sink'])} → {fs(out['split']['sink'])} | {out['none']['V']:.3f} → {out['split']['V']:.3f} |")
+    lines += ["", "## Readings and robustness class", "", "| Reading | " + " | ".join(dm.ANCHORS) + " | class |",
+              "|---|" + "---|" * (len(dm.ANCHORS) + 1)]
+    for phi in sorted({k[0] for k in res}):
+        vals = [res[(phi, a)]["split"]["dec"] for a in dm.ANCHORS]
+        lines.append(f"| decoupled decades with split, φ_r {phi} | " + " | ".join(f"{v:+.2f}" for v in vals)
+                     + f" | {bp.classify(vals, 'sign')} |")
+    lines.append("")
+    (OUT / "dematerialization.md").write_text("\n".join(lines))
+    print("\n".join(lines))
+
+
+if __name__ == "__main__":
+    main()

simulations/gadm02/gadm05.py

@@ -18,6 +18,8 @@ writing, analysis; Anthropic Economic Index), xn = 0.3 (about aX).
 
 from __future__ import annotations
 
+import math
+
 import gadm04 as g4
 
 MODEL_VERSION = "GADM-0.5-dev"
@@ -84,7 +86,9 @@ def _draws(s: dict, a: dict, p: dict, q: dict) -> tuple[float, float, float]:
 # 1 - dm_eps * (qn - qn0), where qn = (Y_n / Y*) * sqrt(X * Q) is the quality-weighted non-rival
 # offer. Physical throughput intensity thr and physical investment aK scale with Cr: the same
 # capital stock serves dematerialized demand with less physical load. dm_lam = 0 switches it off.
-DEM_PARAMS = {"dm_lam": 0.0, "dm_eps": 2.0}
+DEM_PARAMS = {"dm_lam": 0.0, "dm_eps": 2.0, "eff": 0.0}
+# eff (WP-0018-T01): autonomous efficiency trend of physical throughput intensity, per year:
+# thr(t) = thr0 * Cr(t) * exp(-eff t). Compute energy (e2) has no efficiency trend (conservative).
 
 
 def nonrival_quality(s: dict, a: dict) -> float:
@@ -113,8 +117,8 @@ def simulate_eco(params: dict | None = None, init: dict | None = None, eco: dict
     rows = []
     steps = int(round(T / dt))
     for i in range(steps + 1):
-        if qd["dm_lam"]:
+        if qd["dm_lam"] or qd["eff"]:
-            p = {**p, "thr": thr0 * cr, "aK": aK0 * cr}
+            p = {**p, "thr": thr0 * cr * math.exp(-qd["eff"] * i * dt), "aK": aK0 * cr}
         d, a = g4.derivatives(s, p)
         dr, dm, ds = _draws(s, a, p, q)
         d["Er"] = rr * (1 - s["Er"]) - dr * s["Er"]
@@ -124,7 +128,7 @@ def simulate_eco(params: dict | None = None, init: dict | None = None, eco: dict
         if i % record_every == 0:
             row = {"t": round(i * dt, 6), **s, "P": g4.g3.total_p(s), "G": a["Gagg"],
                    **{k: a[k] for k in ("H", "A", "Ystar", "Yr", "Yn", "dem", "B", "V", "Vsel")}, "Cr": cr,
-                   "thru": p["e1"] * s["Kp"] * a["dem"] * p["thr"] + p["e2"] * s["Ko"]}
+                   "thru": p["e1"] * s["Kp"] * a["dem"] * p["thr"] + p["e2"] * s["Ko"], "mat": dm}
             row["VFAC"] = g4.g2.vfac(row)
             rows.append(row)
         if i < steps:

simulations/gadm02/results/dematerialization.md

@@ -0,0 +1,39 @@
+# GADM-0.5-dev: dematerialization against observed resource productivity
+
+Generated by `simulations/gadm02/dematerialization.py` (ASSEMBLY-WP-0018-T01). Observed: material
+intensity (inverse of Eurostat resource productivity, env_ac_rp, chain-linked 2015 EUR per kg DMC),
+2010-2024. Model operator: material draw per unit of output in the first decade from the calibrated
+start (Calibration v0.5) with ecological classes. Total throughput per output is the wrong operator
+(it includes compute energy).
+
+## Fit
+
+| Jurisdiction | observed | model, no split (φ 0.2) | model, split ε 2 (φ 0.2) | φ_r reproducing the observation (split ε 2) |
+|---|---|---|---|---|
+| EU | -1.85 %/y | -2.45 %/y | -2.89 %/y | 0.66 |
+| DE | -2.73 %/y | -2.26 %/y | -2.64 %/y | 0.15 |
+
+## T04 readings at the prior and at the EU-fitted φ_r (generative regime, material replenishment at rest)
+
+| φ_r | Anchor | decoupled decades no split → split | sinks breach no split → split | VFAC no split → split |
+|---|---|---|---|---|
+| 0.2 | B1 | 0.00 → 0.00 | t 83 → none | 0.607 → 0.613 |
+| 0.2 | B2 | 0.00 → 0.45 | t 49 → t 98 | 0.583 → 0.598 |
+| 0.2 | B3 | 0.00 → 0.71 | t 37 → t 61 | 0.564 → 0.585 |
+| 0.2 | B4 | 0.00 → 0.22 | t 29 → t 40 | 0.509 → 0.533 |
+| 0.15 | B1 | 0.00 → 0.00 | t 83 → none | 0.607 → 0.613 |
+| 0.15 | B2 | 0.00 → 0.55 | t 49 → none | 0.583 → 0.599 |
+| 0.15 | B3 | 0.00 → 0.72 | t 37 → t 67 | 0.564 → 0.587 |
+| 0.15 | B4 | 0.00 → 0.24 | t 29 → t 41 | 0.509 → 0.535 |
+| 0.66 | B1 | 0.00 → 0.00 | t 84 → t 100 | 0.606 → 0.608 |
+| 0.66 | B2 | 0.00 → 0.00 | t 49 → t 58 | 0.582 → 0.588 |
+| 0.66 | B3 | 0.00 → 0.00 | t 37 → t 43 | 0.563 → 0.571 |
+| 0.66 | B4 | 0.00 → 0.02 | t 29 → t 33 | 0.506 → 0.515 |
+
+## Readings and robustness class
+
+| Reading | B1 | B2 | B3 | B4 | class |
+|---|---|---|---|---|---|
+| decoupled decades with split, φ_r 0.15 | +0.00 | +0.55 | +0.72 | +0.24 | QUALITATIVE BREAK |
+| decoupled decades with split, φ_r 0.2 | +0.00 | +0.45 | +0.71 | +0.22 | QUALITATIVE BREAK |
+| decoupled decades with split, φ_r 0.66 | +0.00 | +0.00 | +0.00 | +0.02 | QUALITATIVE BREAK |

workplans/ASSEMBLY-WP-0018-gadm05-grounding.md

@@ -4,7 +4,7 @@ type: workplan
 title: "GADM-0.5 grounding: dematerialization, ecological classes, non-rival output"
 domain: communication
 repo: assembly-economics
-status: proposed
+status: active
 flavor: residual
 depends_on: [ASSEMBLY-WP-0007]
 owner: claude-code
@@ -25,11 +25,19 @@ GADM-0.5 replaces GADM-0.4 as the reference model.
 
 ```task
 id: ASSEMBLY-WP-0018-T01
-status: todo
+status: done
 priority: high
 state_hub_task_id: "ba4ac94a-0351-52d7-8dbf-64fd837f8303"
 ```
 
+**Done 2026-10-13:** on the right operator (material draw per output) the
+model reproduces the observed trend without an efficiency trend (the first
+comparison used total throughput, which was wrong). The data constrain φ_r:
+EU 0.66, DE 0.15. At the EU fit, decoupling disappears (BR-011). Weakly
+identified, because 2010–2024 is pre-generative-AI. E5 is wired into the full
+checkpoint (`sources.json`). `dematerialization.py`, `models/GADM-0.5.md` § 5.
+The efficiency parameter `eff` remains available (default 0).
+
 Modeled throughput intensity falls 0.1–0.5 % per year; observed EU
 dematerialization is about 1.6 % per year (resource productivity, Eurostat
 env_ac_rp / env_ac_mfa, 2000–2022; UNEP IRP for US and AR). Add an autonomous