assembly-economics/simulations/gadm02/results/cross_border.md

GADM-0.4: cross-border coupling from the calibrated start (BR-007 test)

Generated by simulations/gadm02/cross_border.py (ASSEMBLY-WP-0011-T05, first part). World US (home of the operators), EU and AR (hosts), from Calibration v0.4. Foreign shares: EU {'Pd': 1.0, 'Pmem': 1.0, 'Plin': 0.9, 'Pi': 0.75}, AR {'Pd': 1.0, 'Pmem': 1.0, 'Plin': 1.0, 'Pi': 0.9}; frontier access κ 0.8 (prior). Legitimacy loop off. P floor 0.70.

Access rule a (per year, on the foreign part of Pd and Pmem) fitted to the observed DMA effect: Google's share fell 3.1 points in the US and 6.5 (DE) / 3.0 (FR) in the EU between Mar 2023-Feb 2024 and Oct 2025-Sep 2026 (StatCounter). EU excess ≈ −1.7 points in 2.5 years → a = 0.0000 (range 0.0000–0.0061 for an excess of 0 to −3.4 points). Without any rule the coupled model already gives an EU excess of -2.6 points (the EU operator part converges toward the operator's home level), so the observed decline is consistent with no DMA effect; the data allow at most a ≈ 0.006. Counterfactual strong rule: a 0.15.

Case	Jurisdiction	P t0 → t25 → t100	Pd / Pmem / Plin t100	K_Ω t25	VFAC t100	G	A	floor
closed model, current levers	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
closed model, current levers	EU	0.70 → 0.77 → 0.82	0.91 / 0.60 / 0.90	0.31	0.288	0.41	0.41	broken
closed model, current levers	AR	0.75 → 0.85 → 0.86	0.95 / 0.79 / 0.90	0.31	0.229	0.34	0.27	broken
coupled, current levers	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, current levers	EU	0.70 → 0.77 → 0.82	0.88 / 0.63 / 0.91	0.31	0.281	0.41	0.42	broken
coupled, current levers	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, DMA as observed (a fitted)	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, DMA as observed (a fitted)	EU	0.70 → 0.77 → 0.82	0.88 / 0.63 / 0.91	0.31	0.281	0.41	0.42	broken
coupled, DMA as observed (a fitted)	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, strong access rule a 0.15 (σ 0)	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, strong access rule a 0.15 (σ 0)	EU	0.70 → 0.61 → 0.68	0.14 / 0.07 / 0.91	0.35	0.332	0.44	0.39	ok
coupled, strong access rule a 0.15 (σ 0)	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, strong access rule, spillover σ 0.5	US	0.68 → 0.70 → 0.75	0.68 / 0.12 / 0.90	0.38	0.279	0.37	0.31	broken
coupled, strong access rule, spillover σ 0.5	EU	0.70 → 0.61 → 0.69	0.14 / 0.07 / 0.91	0.35	0.331	0.44	0.39	ok
coupled, strong access rule, spillover σ 0.5	AR	0.75 → 0.73 → 0.76	0.68 / 0.12 / 0.90	0.33	0.265	0.36	0.26	broken
coupled, US moves to J1 levers	US	0.68 → 0.58 → 0.60	0.86 / 0.02 / 0.28	0.49	0.379	0.46	0.47	ok
coupled, US moves to J1 levers	EU	0.70 → 0.57 → 0.64	0.86 / 0.02 / 0.35	0.38	0.358	0.45	0.38	ok
coupled, US moves to J1 levers	AR	0.75 → 0.63 → 0.66	0.86 / 0.02 / 0.28	0.37	0.303	0.37	0.25	ok
coupled, US J1 + DMA as observed	US	0.68 → 0.58 → 0.60	0.86 / 0.02 / 0.28	0.49	0.379	0.46	0.47	ok
coupled, US J1 + DMA as observed	EU	0.70 → 0.57 → 0.64	0.86 / 0.02 / 0.35	0.38	0.358	0.45	0.38	ok
coupled, US J1 + DMA as observed	AR	0.75 → 0.63 → 0.66	0.86 / 0.02 / 0.28	0.37	0.303	0.37	0.25	ok
coupled, US J1 + strong access rule	US	0.68 → 0.58 → 0.60	0.86 / 0.02 / 0.28	0.49	0.379	0.46	0.47	ok
coupled, US J1 + strong access rule	EU	0.70 → 0.41 → 0.42	0.15 / 0.01 / 0.35	0.43	0.427	0.51	0.35	ok
coupled, US J1 + strong access rule	AR	0.75 → 0.63 → 0.66	0.86 / 0.02 / 0.28	0.37	0.303	0.37	0.25	ok
coupled, EU lineage access rule a 0.15 on Plin	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU lineage access rule a 0.15 on Plin	EU	0.70 → 0.67 → 0.73	0.88 / 0.63 / 0.19	0.34	0.316	0.43	0.40	broken
coupled, EU lineage access rule a 0.15 on Plin	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU lineage portability 0.5	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU lineage portability 0.5	EU	0.70 → 0.77 → 0.83	0.88 / 0.63 / 0.92	0.31	0.283	0.41	0.42	broken
coupled, EU lineage portability 0.5	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU lineage access 0.15 + portability 0.5	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU lineage access 0.15 + portability 0.5	EU	0.70 → 0.70 → 0.76	0.88 / 0.63 / 0.56	0.33	0.310	0.42	0.40	broken
coupled, EU lineage access 0.15 + portability 0.5	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU cloud switching (Data Act) a 0.15 on Pi	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU cloud switching (Data Act) a 0.15 on Pi	EU	0.70 → 0.71 → 0.77	0.88 / 0.63 / 0.91	0.32	0.302	0.42	0.41	broken
coupled, EU cloud switching (Data Act) a 0.15 on Pi	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU all host rules (Pd, Pmem, Plin, Pi 0.15; portability 0.5)	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU all host rules (Pd, Pmem, Plin, Pi 0.15; portability 0.5)	EU	0.70 → 0.36 → 0.35	0.14 / 0.07 / 0.57	0.43	0.438	0.53	0.34	ok
coupled, EU all host rules (Pd, Pmem, Plin, Pi 0.15; portability 0.5)	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.237	0.34	0.26	broken
coupled, endogenous foreign shares, current levers	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, endogenous foreign shares, current levers	EU	0.70 → 0.77 → 0.82	0.88 / 0.63 / 0.90	0.31	0.281	0.41	0.42	broken
coupled, endogenous foreign shares, current levers	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU commons push (IX × 3), fixed shares	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU commons push (IX × 3), fixed shares	EU	0.70 → 0.76 → 0.81	0.88 / 0.63 / 0.91	0.34	0.327	0.42	0.40	broken
coupled, EU commons push (IX × 3), fixed shares	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, EU commons push (IX × 3), endogenous shares	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, EU commons push (IX × 3), endogenous shares	EU	0.70 → 0.76 → 0.81	0.88 / 0.63 / 0.90	0.34	0.326	0.42	0.40	broken
coupled, EU commons push (IX × 3), endogenous shares	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, split hook (domestic segment measured), current levers	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, split hook (domestic segment measured), current levers	EU	0.70 → 0.76 → 0.82	0.88 / 0.63 / 0.90	0.31	0.282	0.41	0.42	broken
coupled, split hook (domestic segment measured), current levers	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, split hook, endogenous shares	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, split hook, endogenous shares	EU	0.70 → 0.76 → 0.82	0.88 / 0.63 / 0.90	0.31	0.281	0.41	0.42	broken
coupled, split hook, endogenous shares	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, split hook, commons push, endogenous shares	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, split hook, commons push, endogenous shares	EU	0.70 → 0.75 → 0.79	0.88 / 0.63 / 0.90	0.34	0.331	0.42	0.40	broken
coupled, split hook, commons push, endogenous shares	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken
coupled, split hook, lineage portability 0.5	US	0.68 → 0.79 → 0.82	0.88 / 0.63 / 0.90	0.36	0.253	0.36	0.32	broken
coupled, split hook, lineage portability 0.5	EU	0.66 → 0.73 → 0.80	0.88 / 0.63 / 0.86	0.32	0.292	0.41	0.41	broken
coupled, split hook, lineage portability 0.5	AR	0.75 → 0.81 → 0.83	0.88 / 0.63 / 0.90	0.32	0.241	0.35	0.27	broken

EU domination at t 100: effect of each lever (coupled model)

Lever	EU P t100	Δ vs. coupled current
coupled, current levers	0.822	+0.000
coupled, DMA as observed (a fitted)	0.822	-0.000
coupled, strong access rule a 0.15 (σ 0)	0.685	-0.137
coupled, strong access rule, spillover σ 0.5	0.685	-0.137
coupled, US moves to J1 levers	0.635	-0.187
coupled, US J1 + DMA as observed	0.635	-0.187
coupled, US J1 + strong access rule	0.417	-0.405
coupled, EU lineage access rule a 0.15 on Plin	0.729	-0.093
coupled, EU lineage portability 0.5	0.825	+0.003
coupled, EU lineage access 0.15 + portability 0.5	0.758	-0.064
coupled, EU cloud switching (Data Act) a 0.15 on Pi	0.767	-0.055
coupled, EU all host rules (Pd, Pmem, Plin, Pi 0.15; portability 0.5)	0.347	-0.475
coupled, endogenous foreign shares, current levers	0.819	-0.002
coupled, EU commons push (IX × 3), fixed shares	0.808	-0.013
coupled, EU commons push (IX × 3), endogenous shares	0.808	-0.014
coupled, split hook (domestic segment measured), current levers	0.818	-0.004
coupled, split hook, endogenous shares	0.819	-0.003
coupled, split hook, commons push, endogenous shares	0.795	-0.027
coupled, split hook, lineage portability 0.5	0.803	-0.019