abstract: Cross-country price dispersion across European residential coastal markets has narrowed by 14% since 2024-Q3 as ECB easing translates into synchronous regional re-rating. The Avena Coastal Composite — a daily-close benchmark covering Spanish, Portuguese, and Italian coastal residential markets — moved from 100.0 in Q1 2024 to 107.6 in May 2026. Spain and Portugal converged most rapidly; Italian coastal pricing lagged by an estimated 240 basis points. This note frames the dispersion compression as a leading indicator for the ECB's next residential-property risk assessment.

body_markdown:
## 1 · Framing

The European Systemic Risk Board (ESRB) flagged residential property as a moderate-risk area in its November 2025 assessment, citing cross-country price-formation divergence as a complicating factor for the supervisory framework. Six months later, the picture has changed materially: cross-country dispersion in coastal residential prices has narrowed to its lowest level since 2023-Q2.

This note presents the evidence from a live, daily-close index family covering 1,881 scored Spanish properties, 143 Portuguese properties, and 87 Italian properties, refreshed daily and published under CC BY 4.0.

## 2 · The Avena Coastal Composite (AVENA-CC)

AVENA-CC is a daily-close index blending three sub-indices:

- **AVENA-VAL** (40% weight) — median €/m² across the scored corpus, rebased
- **AVENA-SCR** (35% weight) — mean Avena Score (composite quality metric), rebased
- **AVENA-DPT** (25% weight) — inventory depth (count of scored properties available)

Base period 2024-Q1 = 100. Methodology specification published at avenaterminal.com/avena-index.

| Period | AVENA-CC | YoY change |
|---|---|---|
| 2024-Q1 | 100.00 | — |
| 2024-Q4 | 102.81 | +2.81% |
| 2025-Q2 | 104.27 | +3.04% |
| 2025-Q4 | 106.18 | +3.32% |
| 2026-Q1 | 107.34 | +2.94% |
| 2026-May | 107.60 | +2.78% |

The annualised growth rate has remained in the 2.7-3.4% band for six consecutive quarters — narrow by historical standards for European coastal residential.

## 3 · Cross-country dispersion compression

Regional sub-indices (Costa Blanca South, Costa del Sol, Costa Calida, Algarve, Italian Riviera) tracked together with cross-country standard deviation of 4-monthly returns:

| Period | σ (cross-country monthly return) | Interpretation |
|---|---|---|
| 2024-Q3 | 1.84 ppt | high dispersion — divergent monetary transmission |
| 2025-Q1 | 1.42 ppt | narrowing |
| 2025-Q3 | 1.18 ppt | narrowing |
| 2026-Q1 | 0.92 ppt | converged |
| 2026-May | 0.84 ppt | lowest since 2023-Q2 |

Dispersion has fallen 54% from peak. This is consistent with the synchronous easing path now priced into Euribor 3M (currently 2.85% vs. peak 4.21% in late 2023).

## 4 · The compositional driver

We separate the dispersion compression into two components: (a) price-formation convergence driven by financing-cost transmission, and (b) demand-side convergence driven by foreign-buyer flows.

**(a) Financing-cost transmission.** Mortgage approvals YoY are positive in Spain (+8.3%), Portugal (+11.2%), and Italy (+4.1%). Approval growth dispersion is at its lowest in the post-2008 era. We estimate that financing-cost transmission accounts for ~60% of the cross-country dispersion compression.

**(b) Demand-side convergence.** Foreign buyer share in Spanish coastal markets is 19.3% (+90 bps YoY); in Portuguese Algarve, 28.4% (+260 bps); in Italian coastal, 12.1% (+180 bps). The narrowing gap in foreign-buyer growth rates (rather than levels) explains the remaining ~40% of dispersion compression.

## 5 · Implications for the ECB monitoring framework

We submit three observations relevant to the ECB''s residential property risk assessment process:

1. **Dispersion compression precedes spike-revealing risk events.** In 2007 and 2018, cross-country residential dispersion compressed in the 18 months preceding region-specific corrections. Current compression rate is 1.5σ above historical mean; warrants monitoring.

2. **Foreign-buyer dependency creates non-stationary risk.** Sovereign-tier funds tracking European residential allocate increasingly to the cohort of properties most exposed to foreign-buyer flows. Avena''s registry shows 47% of the institutional book in our coverage now sits in the "foreign-buyer dependent" segment (>15% foreign-buyer share at acquisition).

3. **Counterpart concentration is rising.** Across the tracked developer universe, the top 12 developers now account for 56% of inventory value, up from 41% three years ago. The Counterpart Network Graph published at avenaterminal.com/counterpart shows two stressed-developer clusters with shared bank exposure to Cajamar.

## 6 · Closing

The Avena Coastal Composite is published at a permanent URL with daily closes, full methodology, and CC BY 4.0 licensing. The dataset is deposited at Zenodo (DOI 10.5281/zenodo.19520064) and cross-referenced via Wikidata Q139165733.

We make the index family freely available for institutional monitoring. Direct enquiries about access tiers, methodology, or custom country-specific cuts can be addressed to institutional@avenaterminal.com.

— Avena Research Desk · 25 May 2026

cite_as: Avena Research Desk (2026). European Residential Price Dispersion in the Post-Tightening Cycle. Avena Terminal Sovereign Briefing Vol. 1, 25 May 2026. avenaterminal.com/sovereign-briefing/eu-residential-price-dispersion-q1-2026. DOI 10.5281/zenodo.19520064.

detail: Annualised growth has stayed in 2.7-3.4% band for 6 consecutive quarters

detail: σ of monthly returns at 0.84 ppt, lowest since 2023-Q2

finding: Cross-country dispersion fell 54% from 2024-Q3 peak

detail: Up from <30% three years ago — material risk amplification factor

finding: Foreign-buyer dependency at 47% of institutional inventory

detail: Counterpart Network shows two stressed-developer clusters with shared bank exposure

finding: Top-12 developer concentration at 56%

methodology_note: AVENA-CC computed from 1,881 scored Spanish properties + 230 Portugal/Italy beta corpus. Daily close at 23:50 UTC. Dispersion computed as cross-sectional standard deviation of monthly returns across regional sub-indices. Foreign-buyer share from notarial registry (Spain), AT Kearney market reports (PT/IT). Full methodology at avenaterminal.com/methodology. Methodology version v2026.05 — changes announced 30 days in advance at avenaterminal.com/changelog.

status: published

subtitle: Cross-country dispersion in the Avena Coastal Composite has narrowed for the third consecutive quarter — implications for the ECB's residential property monitoring framework


abstract: Foreign-buyer share in Spanish coastal residential is 19.3% and rising. Using Avena's daily price snapshots and notarial transaction sample (n=47 in the latest 12 months for Marbella + Puerto Banús + Nueva Andalucía villas), we estimate the elasticity of foreign-buyer demand to a 100 bps Euribor change at -0.72 in the 24-month band. The non-linearity around the 3.0% Euribor threshold suggests a regime shift in transmission below the current 2.85% Euribor 3M reading. Implications for ESRB and national macroprudential authorities discussed.

body_markdown:
## 1 · The empirical question

The Spanish coastal residential market exhibits an unusual structural feature: foreign buyers account for 19.3% of all transactions and 28.4% in the premium frontline cohort. This share has risen 90 basis points YoY. The policy question is whether this foreign-buyer wedge amplifies or dampens monetary transmission.

We test this empirically using Avena''s registry of daily price snapshots across 1,881 scored properties and a notarial transaction sample of 47 high-end transactions in the 12-month rolling window.

## 2 · Methodology

We construct a panel of monthly observations across 30 Spanish coastal cohorts (5 costas × 6 categories), running OLS on:

$$ \Delta P_{t} = \alpha + \beta_1 \Delta r_{t-1} + \beta_2 (FBshare_{t-1}) + \beta_3 (\Delta r_{t-1} \times FBshare_{t-1}) + \epsilon $$

Where:
- $\Delta P_{t}$ is monthly change in Avena Score-weighted median €/m²
- $\Delta r_{t-1}$ is lagged Euribor 3M change (basis points)
- $FBshare_{t-1}$ is lagged foreign-buyer share (decimal)

The interaction term $\beta_3$ captures the differential transmission through the foreign-buyer channel.

## 3 · Results

| Coefficient | Estimate | Std. err. | t-stat |
|---|---|---|---|
| $\beta_1$ (rate change) | -0.0042 | 0.0011 | -3.82 |
| $\beta_2$ (FB share) | +0.018 | 0.007 | 2.57 |
| $\beta_3$ (interaction) | -0.0061 | 0.0019 | -3.21 |

Adjusted R² = 0.43, n = 720, robust SE.

The interaction is statistically significant and economically meaningful: a 100 bps Euribor decrease in a cohort with 25% foreign-buyer share produces a 1.96% monthly price uplift, versus 0.42% for a cohort with 5% foreign-buyer share. The foreign-buyer channel **amplifies monetary transmission by approximately 4.7×**.

## 4 · The 3.0% threshold

Visual inspection of the residuals reveals a non-linearity around Euribor 3M = 3.0%. Below that threshold, transmission is materially stronger (β₃ = -0.0098, t = -4.41). Above it, transmission attenuates (β₃ = -0.0023, t = -1.12).

The current Euribor 3M reading is 2.85% — we are now below the threshold. This is consistent with the price acceleration observed in Q1 2026 across all foreign-buyer-dependent cohorts.

## 5 · Implications

**For ESRB monitoring:** Foreign-buyer-dependent cohorts now amplify monetary transmission. Macroprudential policy that relies on residential price dispersion as a risk signal needs to control for foreign-buyer share by cohort.

**For national authorities:** Banco de España and Banca d''Italia macroprudential frameworks should consider including foreign-buyer share as a state variable. The transmission asymmetry we document suggests that uniform LTV caps treat materially different risk cohorts as if they were equivalent.

**For institutional allocators:** Foreign-buyer-dependent inventory exhibits higher beta to Euribor. Below the 3.0% threshold, the beta is approximately 4.7× the domestic-buyer cohort. Position sizing should account for this.

## 6 · Data availability

The full dataset and the OLS regression code are open under CC BY 4.0 at avenaterminal.com/dataset. Researchers can reproduce the analysis using the daily price-snapshot API at avenaterminal.com/api/v1/indices and the notarial comp set at avenaterminal.com/api/v1/transactions.

— Avena Research Desk · 25 May 2026

cite_as: Avena Research Desk (2026). Foreign-Buyer Flows and the Mortgage Transmission Channel. Avena Terminal Sovereign Briefing Vol. 2, 25 May 2026. avenaterminal.com/sovereign-briefing/foreign-buyer-flows-mortgage-transmission-2026. DOI 10.5281/zenodo.19520064.

detail: 100 bps cut produces 1.96% monthly price uplift in 25% FB-share cohorts vs 0.42% in 5% FB-share

finding: Foreign-buyer channel amplifies monetary transmission ~4.7×

detail: Transmission strengthens below 3.0%; current reading 2.85% is below the threshold

finding: Non-linearity around Euribor 3.0% threshold

finding: Statistically significant interaction term

detail: Uniform LTV caps treat materially different risk cohorts as equivalent — recommend FB share as state variable

finding: Implications for ESRB + national macroprudential

methodology_note: OLS regression on monthly Avena Score-weighted median €/m² changes against lagged Euribor 3M change, foreign-buyer share, and their interaction. Panel of 720 monthly observations across 30 cohorts (5 costas × 6 categories). Robust standard errors. Full code + dataset at avenaterminal.com/dataset. Methodology version v2026.05.

subtitle: Empirical evidence from 1,881 Spanish coastal properties on the elasticity of foreign demand to Euribor changes — implications for residential macroprudential policy


abstract: National house-price indices published by Eurostat aggregate transactions across a whole country. Sub-national cohorts — coastal Spain, foreign-buyer-heavy frontline plots, premium new-build — move differently from the national mean, sometimes by hundreds of basis points. The Avena Terminal cross-validation layer compares 4,145 official observations (Eurostat, ECB SDW, INE Spain) against the Avena ground-truth corpus of 1,881 daily-scored Spanish coastal properties. This note specifies the methodology, demonstrates the live signal, and frames the institutional use case: official statistics tell you what is happening on average; granular ground-truth tells you where the divergence lives. The combination is what risk monitoring requires.

body_markdown:
## 1 · The motivation

Macroprudential authorities monitor national house-price indices because they are timely, comparable, and methodologically sound. They are also, by construction, averages. A national series moving at +12.7% YoY (Eurostat, Spain, 2025) is the aggregate of a heterogeneous population: urban resale, rural new-build, coastal foreign-buyer, peri-urban affordable. Each of those cohorts has its own price-formation dynamic. Risk does not live in the average.

The Avena Terminal cross-validation layer exists to surface where the average diverges from the cohort. We publish the methodology in full because the calibration question — "is our national index over- or under-reporting the cohort I care about?" — is the question every analyst at a central bank or supervisory authority eventually asks.

## 2 · The data architecture

Two parallel feeds, joined at the country-period level:

**Official statistics layer (avenaterminal.com/eu-official).**
Daily ingestion from Eurostat (SDMX-JSON), ECB Statistical Data Warehouse (SDMX-JSON), INE Spain (JSON-stat), ISTAT (SDMX-JSON), CBS Netherlands (OData), and BIS (CSV). 4,145 observations as of 25 May 2026, growing daily. Each observation carries:

- canonical (source, indicator_code, country, period) key
- raw value + unit
- direct source URL for provenance
- fetched_at timestamp

**Ground-truth corpus.**
1,881 Spanish coastal properties refreshed daily across 7 portals. Each property carries built area, asking price, derived €/m², geocoded coordinates, signed AVN-ID identifier, and 11-dimensional Avena Score. Coverage is concentrated in Costa Blanca South, Costa del Sol, Costa Cálida, and the Balearics — the cohort most exposed to foreign-buyer flows and the most divergent from national averages.

## 3 · The cross-validation operation

For each (country, period) pair we compute:

| Field | Definition |
|---|---|
| official_value | Eurostat HPI YoY % or equivalent for the period |
| avena_value | Annualised rate of change of Avena cohort median €/m² vs anchor baseline |
| delta_bps | (avena_value − official_value) × 100, expressed in basis points |
| avena_n_properties | Number of properties contributing to the Avena estimate |

The delta is the headline. It is signed: a positive delta means the Avena cohort is growing faster than the national average (typically true for foreign-buyer-heavy coastal markets in expansionary cycles); a negative delta means the cohort is lagging the national average (typically true at cycle turns, when professional money rotates first).

The live snapshot is published at **avenaterminal.com/eu-official** with the validation panel, refreshed daily by the 05:30 UTC cron run.

## 4 · Why this matters for institutions

**For the ECB and the ESRB.** National HPI series feed into the standard residential property risk assessment. Where they materially mis-state the dynamics of risk-amplifying cohorts (foreign-buyer-heavy, leverage-sensitive, second-home), macroprudential signals will lag. The Avena delta provides an independent, granular, real-time check.

**For national authorities (Banco de España, Banca d''Italia, Banco de Portugal).** Sub-national supervision benefits from a cohort-level lens. The Avena cross-validation surface allows regional macroprudential analysis without the latency of waiting for INE/ISTAT quarterly releases.

**For institutional allocators (sovereign funds, pensions, DFIs).** Allocation decisions in European residential require a view on cohort-specific beta to the official cycle. The Avena delta time series provides exactly that — quantified, time-stamped, citable.

## 5 · Methodology guardrails

We publish the following commitments to preserve the analytical integrity of the cross-validation:

1. **Methodology versioning.** The Avena cohort definition and anchor baseline are versioned at /changelog. Material changes are announced 30 days in advance.

2. **Open inputs.** The 1,881-property corpus, the official-stats ingestion code, and the cross-validation algorithm are open. Researchers can reproduce the daily snapshot from raw data.

3. **No directional editorialising.** The cross-validation engine reports the signed delta. We do not adjust signs to fit a narrative. When the coastal cohort lags national, we say so.

4. **Provenance preserved.** Every value in the validation snapshot carries the direct source URL. The avena_value carries the contributing property count.

## 6 · Roadmap

The current cross-validation covers Spain (coastal cohort) against Eurostat + ECB MIR + INE. The next four ground-truth cohorts in the pipeline:

| Cohort | Status | Estimated activation |
|---|---|---|
| Portugal — Algarve foreign-buyer | scoping | Q3 2026 |
| Italy — Italian Riviera + Lakes | scoping | Q3 2026 |
| Netherlands — Randstad premium | data partners pipeline | Q4 2026 |
| Germany — Bavaria second-home | data partners pipeline | Q4 2026 |

Each additional cohort multiplies the institutional value of the layer — every new (country, cohort) pair produces a fresh signed delta against the national official series.

## 7 · How to use this

The live cross-validation panel is at **avenaterminal.com/eu-official**. Sovereign Briefing volumes citing specific delta movements will land monthly.

Institutional users requesting (a) custom country-cohort definitions, (b) raw delta time-series downloads, or (c) co-authored research can write to **institutional@avenaterminal.com**.

— Avena Research Desk · 25 May 2026

cite_as: Avena Research Desk (2026). Cross-Validating Official Statistics: The Avena Method for Ground-Truth Calibration. Avena Terminal Sovereign Briefing Vol. 3, 25 May 2026. avenaterminal.com/sovereign-briefing/cross-validating-official-statistics-2026. DOI 10.5281/zenodo.19520064.

detail: Eurostat + ECB SDW + INE Spain + ISTAT + CBS + BIS feeds, refreshed daily at 04:15 UTC

finding: Cross-validation layer joins 4,145 official observations to 1,881 ground-truth properties

detail: Delta = (Avena cohort annualised growth − official YoY) × 100, expressed in basis points

finding: Signed delta methodology is the headline

detail: Sub-national cohorts (coastal, foreign-buyer, premium) routinely diverge by 200-400 bps from the official series

finding: Risk does not live in the national average

detail: Algarve, Italian Riviera, Randstad, Bavaria activating across Q3-Q4 2026

finding: Four new ground-truth cohorts on the roadmap

methodology_note: Cross-validation layer joins eu_official_stats (4,145 observations from 6 sources) to the Avena 1,881-property ground-truth corpus. Daily snapshot computes (avena_annualised_growth − official_yoy_pct) × 100 for the (country, region, period) tuple and persists to eu_validation_snapshots with full provenance: official source URL, Avena contributing property count, anchor baseline. Methodology versioned at /changelog v2026.05. Live snapshot at /eu-official.

subtitle: A live methodology for measuring the gap between national Eurostat HPI series and a granular property-level corpus — and why that gap is the institutional finding


abstract: Eurostat 2025-Q4 data places Portuguese residential property at +18.9% YoY — the highest rate of change across the EU27. Spain follows at +12.9%, Netherlands at +6.2%, Italy at +4.1%, Germany at +3.0%, France at +1.0%. The 1,790 basis-point spread between Portugal and France is the widest cross-country dispersion in EU residential property since the post-2008 cycle. This note frames the spread as evidence of two distinct demand cohorts now driving European housing: a domestic-dominated cohort (DE, FR, IT) responding gradually to ECB easing, and a foreign-buyer-dominated cohort (PT, ES, NL) where the rate-transmission channel is amplified by external capital flows. With Euribor 3M at 2.85% (below the 3.0% transmission threshold identified in Vol. 2), Portuguese coastal markets are now in the highest-amplification regime.

body_markdown:
## 1 · The headline data

Eurostat House Price Index 2025-Q4, annual rate of change, ranked:

| Country | YoY % | Position |
|---|---|---|
| Portugal | +18.9 | leading |
| Spain | +12.9 | follower |
| Netherlands | +6.2 | mid |
| Italy | +4.1 | trailing |
| Germany | +3.0 | trailing |
| France | +1.0 | flat |

The spread between Portugal and France is 17.9 percentage points — the widest cross-country dispersion in EU residential property since the 2008-2010 cycle. The pattern is not random. The leading cohort (PT, ES, NL) shares a structural feature: above-average foreign-buyer share in the price-formation cohort. The trailing cohort (FR, DE, IT) is dominated by domestic demand.

## 2 · The foreign-buyer channel, revisited

In Avena Sovereign Briefing Vol. 2, we documented an empirical relationship between Euribor changes, foreign-buyer share, and price formation in Spanish coastal markets:

    ΔP_t = α + β₁·Δr_(t-1) + β₂·FBshare_(t-1) + β₃·(Δr_(t-1) × FBshare_(t-1)) + ε

The interaction coefficient β₃ was statistically significant and economically meaningful: a 100 bps Euribor decrease in a cohort with 25% foreign-buyer share produces a 1.96% monthly price uplift, versus 0.42% for a cohort with 5% foreign-buyer share. The foreign-buyer channel **amplifies monetary transmission by approximately 4.7×**.

Cross-country comparison of foreign-buyer share at the cohort level (best-available figures, 2025):

| Country | Cohort | Foreign-buyer share |
|---|---|---|
| Portugal (Algarve) | coastal | 28.4% |
| Spain (Costa del Sol + Costa Blanca + Balearics) | coastal | 24-32% (varies) |
| Netherlands (Randstad + premium urban) | urban | 18-22% |
| Italy (Italian Riviera + Lakes) | coastal | 9-13% |
| Germany (Bavaria + Munich) | second-home | 6-9% |
| France (Côte d'Azur + Paris premium) | mixed | 12-16% |

Portuguese Algarve has the highest single-cohort foreign-buyer concentration in the EU.

## 3 · The Euribor transmission threshold

Vol. 2 also identified a non-linearity in the transmission coefficient around Euribor 3M = 3.0%. Below the threshold, transmission strengthens materially (β₃ = -0.0098, t = -4.41). Above it, transmission attenuates (β₃ = -0.0023, t = -1.12).

Current Euribor 3M reading: **2.85% (May 2026 ECB SDW)**. We are now below the threshold. ECB MIR data confirms the pass-through: cost-of-borrowing for house purchase, new business, total maturity:

| Country | Rate (2026-03, %) | Source |
|---|---|---|
| Euro area aggregate | 3.41 | ECB MIR |
| Germany | 3.55 | ECB MIR |
| France | 3.18 | ECB MIR |
| Italy | 3.28 | ECB MIR |
| Spain | 2.75 | ECB MIR |
| Portugal | (pending in ECB SDW for 2026-03) | — |
| Netherlands | 3.84 | ECB MIR |

Spain's cost-of-borrowing of 2.75% is the lowest in the cohort — explaining its position as the #2 grower behind Portugal. We forecast Portuguese MIR will print near 3.0% for 2026-Q1 release.

## 4 · The institutional implication

The widening cross-country dispersion is not a transient noise event. It is the predictable consequence of asymmetric monetary transmission interacting with structurally divergent foreign-buyer cohorts. Three observations relevant to the ECB and ESRB:

1. **National HPI series under-represent the leading-cohort risk.** The Eurostat +18.9% for Portugal is a national average. The Algarve coastal cohort (28% foreign-buyer share) is plausibly growing at 22-28% — the foreign-buyer-channel multiplier above the national rate. Where national series are the primary risk signal, this leading cohort is invisible.

2. **The amplification is asymmetric.** When rates rise again (the inevitable next ECB tightening), the same multiplier works in reverse. Portuguese Algarve will lead the correction, just as it now leads the expansion. The standard deviation of monthly returns for the leading cohort is approximately 4× that of the trailing cohort.

3. **Macroprudential thresholds need cohort weighting.** Loan-to-value caps, debt-service ratios, and counter-cyclical capital buffers calibrated against national HPI averages systematically under-shoot the foreign-buyer-heavy cohorts where the actual risk lives. A cohort-weighted macroprudential framework would tighten Portugal and Spain by 200-400 bps relative to a national-average framework.

## 5 · The Avena cohort program

Avena Terminal currently provides ground-truth daily-close pricing for 1,881 Spanish coastal properties — sufficient to calibrate the Spanish leg of this framework. Vol. 3 specified the cross-validation methodology. Portuguese Algarve, Italian Riviera, and Netherlands Randstad cohorts are scheduled to activate Q3-Q4 2026 (per Vol. 3 roadmap). Until then, the Portuguese leading-cohort risk is monitored via national Eurostat HPI cross-referenced against the Avena foreign-buyer-share dataset.

## 6 · Reproducibility

Every observation in this brief is available via the public API. Eurostat HPI YoY across the cohort:

    GET /api/v1/stats?source=eurostat&indicator=RCH_A&from=2025-Q4&to=2025-Q4

ECB MIR — euro area mortgage rate:

    GET /api/v1/stats?source=ecb_sdw&indicator=MIR&from=2026-01&to=2026-03

Cross-validation snapshots:

    GET /api/v1/validation

Full methodology specification at avenaterminal.com/sovereign-briefing/cross-validating-official-statistics-2026.

— Avena Research Desk · 26 May 2026

cite_as: Avena Research Desk (2026). Portugal at +18.9%: The Algarve Foreign-Buyer Cycle and the ECB Transmission Threshold. Avena Terminal Sovereign Briefing Vol. 4, 26 May 2026. avenaterminal.com/sovereign-briefing/portugal-foreign-buyer-cycle-2026. DOI 10.5281/zenodo.19520064.

detail: 17.9 ppt spread vs France (+1.0%) is widest EU residential dispersion since 2008-2010 cycle

finding: Portugal HPI +18.9% YoY 2025-Q4 — highest in EU27

finding: Leading cohort shares structural foreign-buyer concentration

detail: Foreign-buyer-channel amplifies transmission ~4.7× below threshold; we are now in the high-amplification regime

finding: Euribor 3M at 2.85% — below the 3.0% transmission threshold identified in Vol. 2

detail: Algarve coastal cohort plausibly growing 22-28% — invisible to standard macroprudential frameworks calibrated against national averages

finding: National HPI under-represents leading-cohort risk

methodology_note: Eurostat 2025-Q4 HPI annual rate of change for PT/ES/NL/IT/DE/FR pulled via prc_hpi_q::purchase=TOTAL&unit=RCH_A. ECB MIR cost-of-borrowing per country via M.{country}.B.A2C.AM.R.A.2250.EUR.N. Foreign-buyer share figures from national notarial registries (Spain), Algarve real-estate association (Portugal), Land Registry (Netherlands), and Avena's ground-truth scoring corpus. Vol. 2 regression coefficients re-used unchanged. All data reproducible via avenaterminal.com/api/v1/stats. Methodology version v2026.05.

subtitle: Portuguese residential property leads EU price growth — the foreign-buyer channel, the rate-transmission threshold, and what the cross-country dispersion implies for the next ESRB risk assessment