Why Cleaner Technology May Look Like a Luxury Good

Clean technology isn’t just an environmental choice; it’s a financial one. Research from two Duke economists finds that the biggest barrier to adopting cleaner, more efficient equipment is often not awareness or willingness, but access to capital. 

Because greener technologies typically cost more upfront even if they save money over time, companies and households with limited cash or credit are pushed toward cheaper, more polluting options. The result is an uneven transition to a low-carbon economy, in which wealthier actors adopt cleaner technologies faster while financially constrained ones fall behind.

“Those who invest in cleaner technologies don’t do that because they care more,” said Adriano Rampini, the Douglas and Josie Breeden Professor of Financial Economics at Duke University’s Fuqua School of Business. “It’s because it is relatively cheaper for them to do so.”

In the NBER paper, Financing the Adoption of Clean Technology, Rampini and Duke Economics’ Associate Professor Andrea Lanteri show why financing constraints such as down payments and collateral requirements are among the biggest barriers to green tech adoption, as cleaner technologies save money over time but require more cash up front.

The researchers also argue that some climate policies, including subsidized “green lending” programs, are often imperfect and regressive tools that ultimately benefit those who can afford more expensive technology.

A clean and dirty technology mix

Throughout the economy, newer, cleaner equipment operates alongside older and less efficient machines.

“An older car is cheaper to buy upfront, even if it eventually costs more in repairs and fuel,” Rampini said. “A lower-quality couch may wear out faster than an expensive one, but it is easier to afford today.”

The same logic applies to firms.

A large company with abundant capital can invest in durable, energy-efficient equipment that lowers operating costs over time. A smaller firm with tighter financing may instead buy cheaper machinery that consumes more fuel or requires more maintenance later.

The researchers argue that this is not irrational behavior. Financially constrained firms are making economically sensible choices under the limits they face.

That rationality creates a pattern of technology adoption: well-capitalized firms end up operating cleaner technologies, while constrained firms hold onto dirtier and older assets. 

A real-world example: Cargo ships

The researchers observed this pattern in one of the most carbon-intensive industries: commercial shipping.

Ships are expensive, long-lived assets, and newer ship designs have become significantly more energy efficient over time.

The researchers compiled data on the global commercial fleet, including fleet size, ship age, and new ship orders.

Their findings closely matched the theory.

Larger fleets operated significantly cleaner ships than smaller fleets. In some cases, the carbon emission intensity of the smallest fleets was roughly double that of the largest fleets.

The gap appeared for two reasons.

First, larger firms were more likely to purchase cleaner ships when investing in new vessels. Among the smallest fleets, virtually none of the new ship orders had low-emission engines. Among the largest fleets, about 75 percent of new orders were “eco” ships.

Second, larger firms also operated newer fleets overall—closer to 10 years old on average—compared with roughly 20 years old for smaller firms.

That difference matters because shipping technology improves rapidly over time. According to the paper, shipping emissions intensity fell by more than 40 percent between 2005 and 2020.

The result is that smaller firms are “dirtier” in two ways at once: they buy less-efficient equipment when investing in new assets, and they hold onto older equipment longer.

The researchers called this “an induced preference.” Smaller companies don’t have enough cash or access to loans, so they are pushed toward dirtier technology.

Three future scenarios

After documenting those patterns in shipping data, the researchers used their model to simulate how different kinds of technological progress could reshape the green transition.

One scenario assumed that both clean and dirty technologies became more energy efficient over time. Another assumed that only clean technologies improved dramatically. A third explored what happens when clean technology becomes cheaper to produce.

They found that when all technologies become more efficient together, and dirty technology becomes clean enough, firms might stop buying the expensive technology because its relative advantage narrowed. 

In the second scenario, when clean technology alone improved, wealthier companies might buy even more clean technology, widening the gap with smaller firms.

But when clean technology becomes cheaper, such as with cheaper electric batteries, the transition might accelerate more broadly across the economy, and even “poor” companies may be able to afford it.

Still, even cheaper technology couldn’t fully eliminate the underlying financial constraints, the researchers noted. Throughout the simulations, firms with lower net worth would keep relying more heavily on dirtier, older assets. 

Why capital costs matter

One of the paper’s central arguments is that climate policies often focus on the wrong financial variable.

At first glance, lowering borrowing costs for green investments seems like an obvious solution. If banks offer lower interest rates on clean technology loans, more firms should adopt cleaner equipment.

Rampini argues that the deeper obstacle is not the interest rate but the down payment.

“The down payment is a barrier,” he said. Even if a green loan comes with a slightly lower interest rate, many constrained firms still cannot afford the upfront investment cost.

The paper also emphasizes collateral requirements. Banks lend against assets they can repossess in case of default. Ideally, if assets could be collateralized at 100 percent of their value, the down payment concerns would disappear.

But in the current world of collateralization, there are limits on how much lenders can safely finance.

In maritime shipping, several major lenders have adopted the Poseidon Principles, a framework that encourages financing for lower-emission vessels. Rampini said these initiatives may still disproportionately benefit firms that are already financially strong enough to buy cleaner ships.

“If you’re a green lender,” he said, “what it essentially means is that you’re providing relatively cheap capital to firms that already have a lot of capital.”

The same logic applies to climate policies for consumers.

Rampini pointed to California’s solar-panel incentives as an example. For years, homeowners with rooftop solar could sell excess electricity back to the grid at favorable retail prices. But installing solar panels first required owning a home and paying the upfront installation costs.

As more affluent households reduced their electricity bills, more of the grid’s fixed costs shifted onto households without solar panels.

“The entire cost of operating the grid,” Rampini said, “was paid by the people who didn’t have solar panels on the roof.”

The legal barriers to going green

Rampini argues that weak legal systems can make clean-technology adoption significantly harder. In countries where repossessing collateral is slow or uncertain, lenders extend less credit because recovering assets after default becomes costly and unpredictable.

“If it’s very hard to repossess anything,” Rampini said, “then I can’t lend you very much.”

That dynamic pushes firms toward cheaper, less efficient technologies that require smaller upfront commitments.

The argument extends to other policies currently debated in shipping. The International Maritime Organization is considering what could become the world’s first global carbon-pricing system for the sector. The proposed framework would charge ships exceeding emissions benchmarks, creating financial incentives for more efficient vessels.

But Rampini’s research suggests that even carbon taxes may affect firms unevenly, favoring larger shipping companies with the financial capacity to modernize fleets quickly.

For all these reasons, the researchers argue that improving legal and financial systems may be as important as climate subsidies themselves.

Better collateral laws, stronger repossession systems, and more reliable legal enforcement could expand access to financing for cleaner assets, Rampini said. 

“The transition to cleaner technology may depend not only on engineering breakthroughs or environmental targets, but also on the financial architecture underneath the economy itself,” he said.