BLI: The tail that wags the dog
By Guy Wagner, Chief Investment Officer at Banque de Luxembourg Investments (BLI)
There was a time when the stock market reflected the economy. It moved up and down as a consequence of underlying business conditions: profits, investment, productivity, and growth. The economy was the “dog,” and the market was the “tail.” That relationship has quietly reversed.
Today, the stock market is no longer just a mirror of the U.S. economy. In many ways, it has become a driver of it, to the point where a prolonged bear market is no longer something the system can easily tolerate. The tail is now wagging the dog.
A Financialized Economy
Over the past few decades, the U.S. economy has become deeply financialized. Household wealth is heavily tied to financial assets, especially equities. Corporate behavior is shaped by share prices through stock-based compensation, buybacks, and investor expectations. Even consumption, once driven primarily by income, is now influenced by the so-called “wealth effect.”
When markets rise, people feel richer and spend more. When markets fall, they pull back. This is not theoretical; it is visible in the data across market cycles.
In this context, a sustained bear market would no longer be just a financial event. It would become a macroeconomic shock. Less obvious, but just as important, is the government’s exposure.
Tax revenues have become increasingly linked to the stock market. Capital gains taxes, in particular, are highly sensitive to market levels. When markets rise, revenues surge. When markets fall, they evaporate.
Higher equity prices sustain the broader financial ecosystem that feeds into taxable income. A prolonged decline in equities would therefore not just hurt investors—it would also be fiscally destabilizing. In effect, the U.S. Treasury has become a silent partner in the stock market. Not through ownership, but through dependence.
Pensions, Demographics, and Fragility
Then there is the issue of pensions.
Both public and private retirement systems in the U.S. are heavily exposed to equities. Over time, allocations have increased in an attempt to meet return assumptions that are, in many cases, far too optimistic.
And now demographics are turning that exposure into a constraint: an aging population is increasingly dependent on these assets.
In a younger society, a bear market can be an opportunity: more time to accumulate assets at lower prices. In an older society, it is a threat. Losses are realized, not deferred. Withdrawals continue regardless of market conditions.
This creates a structural vulnerability: the system increasingly needs markets to continue rising at a time when equity valuations are already high. At the same time, it is becoming less able to withstand prolonged declines.
The Unspoken Mandate: An Implicit Backstop
Put these pieces together—financialized households, tax dependence, pension exposure—and a pattern emerges. Policymakers may not explicitly target the stock market, but they cannot ignore it either.
When markets fall sharply, the response is predictable and tends to follow a familiar script:
- Monetary policy loosens
- Liquidity is provided
- Balance sheets expand
- Fiscal support is considered or increased
- Communication shifts from fiscal and monetary discipline to support
This is not necessarily a conspiracy or a formal mandate. It is a constraint. When so much of the system depends on asset prices, stabilizing markets becomes synonymous with stabilizing the economy.
Over time, this creates an implicit backstop: a widespread belief that severe and lasting declines will be met with intervention. That belief then influences investor behavior. If investors believe that large drawdowns will be cushioned, risk-taking increases. Valuations expand. Leverage builds.
The system becomes more sensitive to asset prices, which in turn strengthens the incentive to prevent declines. Fragility accumulates beneath the surface. Moral hazard becomes a feature—rather than an unfortunate byproduct—of intervention.
It is a self-reinforcing dynamic. Ironically, the very mechanisms designed to stabilize the system make it more dependent on continued intervention.
Of course, markets can still fall. But the question is not whether short-term corrections are possible. It is whether a deep and prolonged bear market—the kind that resets expectations, compresses valuations, and purges excesses—can still be allowed to run its course.
Because a true bear market would no longer be just about investors losing money. It would also mean:
- Consumers pulling back
- Tax revenues shrinking
- Pension gaps widening
- Confidence eroding across the board
The tolerance for this appears very low. On the contrary, the threshold at which broader economic or policy responses are triggered seems to move ever higher.
What This Means
If the stock market has become systemically important in this way, it changes how we should think about it.
It is no longer just a pricing mechanism for allocating capital or discounting future cash flows. It is also:
- A driver of consumption
- A source of government revenue
- A pillar of retirement systems
- A key input into policy decisions
In other words, it is no longer just a market. It has become part of the infrastructure.
And infrastructures, by their nature, are not allowed to fail.
The Ironic Endgame
The irony is difficult to miss: in trying to stabilize the system, we have made it more dependent on stability - and on continuous intervention. In preventing declines, we have reduced the system’s ability to absorb them.
The tail wags the dog not because anyone designed it that way, but because, step by step, dependency replaced resilience.
The question is no longer whether markets matter, but whether they matter too much.
When Confidence in Policy Evaporates
But this entire framework rests on one critical assumption: that policymakers remain not only willing, but able to intervene effectively.
If confidence in that assumption begins to erode—whether because of inflation constraints, political gridlock, balance-sheet limits, or diminishing policy effectiveness—the consequences could be nonlinear.
Markets do not respond only to actions; they also respond to belief in those actions. If that belief weakens, the implicit backstop disappears. Risk premia could rise sharply, valuations could compress simultaneously across asset classes, and volatility could become more persistent rather than episodic.
In such a scenario, policymakers might still act—but their actions could have diminishing impact. Instead of stabilizing markets, interventions could be interpreted as signs of weakness or desperation.
The result would be a regime shift: from a system anchored by confidence in intervention to one defined by uncertainty about its limits.
And in that world, the tail would not just wag the dog—it could drag it down.