Global Growth Cycle: OECD Data Meets Tactical Allocation
Most tactical strategies rely on price-based signals — momentum, moving averages, or relative strength. The Global Growth Cycle (GGC) family takes a fundamentally different approach: it uses macroeconomic data from the Organisation for Economic Co-operation and Development (OECD) to determine whether the global economy is expanding or contracting, then positions accordingly. The result is a strategy that responds to economic reality rather than market sentiment, often positioning ahead of turning points that price-based signals detect only after significant moves have already occurred.
Two implementations exist on the platform: the base GGC, which makes a simple binary equity-or-cash decision, and GGC Enhanced (GGC_ENH), which adds relative strength ranking and international diversification to the macro framework.
The OECD Composite Leading Indicator
The OECD publishes Composite Leading Indicators (CLIs) for each of its member countries and major partner economies. These indicators are designed to anticipate turning points in the business cycle relative to trend, typically leading GDP by 6 to 9 months. Each country's CLI is constructed from a basket of economic series — order books, building permits, interest rate spreads, equity prices, consumer confidence — selected specifically for that country's economic structure.
What matters for the GGC strategy is not the absolute level of any single country's CLI, but whether it is rising or falling. A rising CLI indicates that the economy is accelerating relative to its trend. A falling CLI suggests deceleration.
The Diffusion Index
The GGC strategy aggregates individual country signals into a single Diffusion Index (DI). The DI measures the percentage of OECD countries whose CLI is rising. If 30 out of 40 tracked countries have rising CLIs, the DI is 75%. If only 15 are rising, the DI is 37.5%.
The DI captures something that no single-country indicator can: the breadth of global economic momentum. A high DI means growth is broad-based and self-reinforcing. A low DI means contraction is spreading and likely to persist. The threshold is 50% — a simple majority.
GGC: The Base Strategy
| Parameter | Value |
|---|---|
| Risk-On Asset | SPY (US large cap) |
| Risk-Off Asset | BIL (T-bills / cash) |
| Protection | MACRO_CLI (OECD diffusion index) |
| Signal Rule | DI > 50% → SPY; DI ≤ 50% → BIL |
The base GGC is deliberately minimal. Each month the engine computes the OECD CLI diffusion index. If more than half of the tracked countries have rising CLIs, the portfolio holds 100% SPY. If half or fewer are rising, the portfolio moves entirely to BIL (T-bills). There is no momentum ranking, no relative strength comparison, and no multi-asset diversification. It is a pure macro timing strategy.
This binary simplicity is both its strength and its limitation. The strength is clarity: the strategy makes one decision based on one signal, and that signal is grounded in real economic data rather than market prices. The limitation is that it offers no nuance — the portfolio is either fully invested in US equities or fully in cash, with nothing in between.
Why Macro Timing Works Differently
Price-based momentum signals are inherently reactive. A 12-month return can only turn negative after the market has already fallen significantly. By contrast, OECD leading indicators are designed to anticipate economic turning points. When the diffusion index drops below 50%, it often signals a slowdown that has not yet been fully reflected in equity prices. This forward-looking characteristic gives GGC a structural advantage during the critical transition periods between expansion and contraction.
The trade-off is that the OECD data is published with a lag — typically 2 to 3 months — and is subject to revision. The engine uses the most recently available data at each rebalance date, which means the signal reflects economic conditions as they were known at the time, not as they might later be revised.
GGC Enhanced: Adding Momentum and Diversification
| Parameter | Value |
|---|---|
| Risk-On Assets | SPY (US large cap), VXUS (international ex-US) |
| Risk-Off Assets | IEF (intermediate Treasuries), BIL (T-bills) |
| Top-N | 1 |
| Lookback | 12 months |
| Momentum Method | REL_STR_1P (12-month relative strength) |
| Protection | MACRO_CLI (OECD diffusion index) |
GGC Enhanced layers momentum ranking on top of the same OECD macro framework. The macro signal still governs the risk-on versus risk-off decision, but within each regime, the strategy selects the best-performing asset using 12-month relative strength.
Step-by-Step Logic
- Compute the OECD CLI Diffusion Index: Same calculation as base GGC — percentage of countries with rising CLIs.
- If DI > 50% (growth regime): Compare the trailing 12-month returns of SPY and VXUS. Hold 100% of whichever has the higher return. This adds geographic rotation — when international markets are outperforming, GGC_ENH captures that trend rather than being locked into US equities.
- If DI ≤ 50% (contraction regime): Compare the trailing 12-month returns of IEF and BIL. Hold 100% of the better performer. This provides defensive rotation — during periods of falling rates, IEF (which benefits from rate declines) will typically outperform BIL. During rising rates, BIL's stability wins.
The Enhancement Over Base GGC
The enhanced version addresses both of the base strategy's limitations. First, it adds international diversification on the equity side. During periods when non-US markets are leading — as they were in 2003-2007 and again in parts of 2017 — GGC_ENH rotates into VXUS rather than being constrained to SPY. Second, it adds intelligence on the defensive side. Rather than always holding cash (BIL), it can rotate into intermediate Treasuries (IEF) when bonds are in an uptrend, capturing additional return during risk-off periods.
For investors interested in how macro signals compare to price-based trend filters, the trend following and SMA strategies article provides a detailed comparison of these two approaches to market timing.
When Macro Signals Diverge from Price
One of the most interesting aspects of the GGC family is what happens when macro signals and price signals disagree. In early 2020, for example, the OECD diffusion index was already declining before the COVID crash hit equity prices. Conversely, macro indicators sometimes lag during sharp V-shaped recoveries, keeping GGC in cash even as markets rebound aggressively.
This divergence is not a flaw — it is a feature of using a fundamentally different information source. Price-based strategies and macro-based strategies tend to make errors at different times, which makes them valuable as components in a blended portfolio. A blend that combines a momentum strategy with GGC can achieve better risk-adjusted returns than either component alone, precisely because their error patterns are uncorrelated.
Practical Considerations
The GGC family trades infrequently. Macro regimes tend to persist for months or even years, so the strategy may hold the same position for extended periods. This makes it exceptionally tax-efficient and easy to implement.
The primary risk is regime mismatch during transitional periods. The OECD data's publication lag means the strategy is always working with slightly stale information. In fast-moving markets, this lag can result in delayed entries or exits. Pairing GGC with a faster, price-based strategy — such as those in the dual momentum family — can help smooth these transitional periods.
For investors who believe that economic fundamentals ultimately drive market returns, the Global Growth Cycle strategies offer a compelling alternative to purely technical approaches. The OECD diffusion index provides a genuine informational edge: it captures the breadth of global economic activity in a single number and positions the portfolio accordingly.