39. Path Dependence and the Pipes Below

Research

🔁 Path Dependence and the Pipes Below: Why Halifax’s Sewer System Is So Hard to Change

Why do some public systems persist, even when they no longer work well? Why do outdated technologies hang on, despite environmental or social costs?

Welcome to the world of path dependence, where yesterday’s decisions quietly shape today’s urban reality.

🛤️ What Is Path Dependence?

Path dependence is the idea that once a society commits to a particular technology or policy, it becomes increasingly difficult to change direction—even if better options arise later.

In Halifax, Nova Scotia, this concept comes to life through the city’s sewerage system. What began as a public health measure in the 19th century has since hardened into a rigid infrastructure and policy framework. This framework has proven resistant to change, despite clear signs that it’s ecologically unsustainable.

📈 Degrees of Dependence: How Deep Are We In?

Economists Liebowitz and Margolis describe three degrees of path dependence:

First-degree: Early choices shape the system, but remain efficient.

Second-degree: Early choices become inefficient over time, but retrofits are possible.

Third-degree: Poor decisions were made despite better alternatives at the time.

Halifax’s wastewater history checks all three boxes. Initially, sewerage helped eliminate waterborne disease—a major public health win. But over time, this same system contributed to long-term pollution in Halifax Harbour. Even when more ecologically sound technologies became available, the system’s history made alternatives nearly impossible to implement.

🧱 Stability or Obdurancy?

Supporters of the current system might argue it’s stable: it works, it’s reliable, and it’s saved lives. But critics see obdurancy: a rigid, outdated setup that resists reform. Both are true—depending on where you stand.

This dual perspective is especially visible in Halifax:

From one angle, the sewer system made the city livable and slashed disease rates.

From another, it closed beaches, killed fisheries, and polluted the harbour for decades.

In the middle, we see a kind of stalemate: a system too embedded to replace, yet too flawed to celebrate.

This is the hallmark of path dependence—not just old pipes, but a deep entrenchment of ideas, technologies, and institutions.

Sewers are more than infrastructure. They’re sociotechnical systems—complex webs of technology, people, politics, and culture.

Who controls these systems? Sociotechnical theory points to three types of actors:

Core actors: city councils, engineers, health officials—those who built and now defend the system.

Enactors: reformers and activists, like the Metro Coalition for Harbour Cleanup, who propose alternatives.

Fringe actors: marginalized communities and individuals excluded from meaningful influence—like the residents of Africville.

The interplay between these groups determines what changes—and what doesn’t.

🚫 Inclusion and Exclusion

In theory, all actors in a policy network should have influence. In practice, power is rarely shared evenly.

In Africville, exclusion was overt—decisions were made with no input from the community.

In the Halifax Harbour Cleanup Initiative, exclusion was more subtle: public participation appeared robust, but in reality had no impact on final decisions.

This pattern reveals not only the technical rigidity of path dependence, but the political and social rigidity that accompanies it.

🌊 Why This Matters Now

As we face climate change, environmental degradation, and aging infrastructure, understanding path dependence helps us see what holds back sustainable reform.

Halifax’s wastewater story shows that changing infrastructure isn’t just about money or technology—it’s about history, power, and entrenched ways of thinking.

To build greener, fairer cities, we must learn not only to innovate, but to break with the past when necessary. That means questioning not just what we’ve built, but why we built it—and for whom.