Columbia Business School Research

We develop a financial-economic model for carbon pricing with an explicit representation of decision making under risk and uncertainty that is consistent with the Intergovernmental Panel on Climate Change’s sixth assessment report. We find that this approach provides economic support for the warming targets in the Paris Agreement across a variety of specifications. We show that risk associated with high damages in the long term leads to stringent mitigation of carbon dioxide emissions in the near term.

Moral hazards are ubiquitous. Green ones typically involve technological fixes: Environmentalists often see ‘technofixes’ as morally fraught because they absolve actors from taking more difficult steps toward systemic solutions. Carbon removal and especially solar geoengineering are only the latest example of such technologies. We here explore green moral hazards throughout American history. We argue that dismissing (solar) geoengineering on moral hazard grounds is often unproductive.

We exploit regional variations in exposure to heat stress to study if physical climate risk is priced in municipal and corporate bonds as well as in equity markets. We find that local exposure to damages related to heat stress equaling 1% of GDP is associated with municipal bond yield spreads that are higher by around 15 basis points per annum (bps), the effect being larger for longer-term, revenue-only and lower-rated bonds, and arising mainly from the expected increase in energy expenditures and decrease in labor productivity.

Climate change brought on by human activities lead to acute and chronic hazards that threaten the planet; to reduce the chances of the most dangerous and irreversible damage, the global community must reduce the emission of greenhouse gases, notably carbon dioxide. While more than 70 countries (~80% of global CO2 emissions and ~90% of global GDP) and over 5,000 influential companies have adopted net-zero commitments, coordination of an effort to this scale, given the complex economic, societal, governance and infrastructure considerations, is no easy feat.

Emissions control cannot address the consequences of global warming for weather disasters until decades later. We model regional-level mitigation or adaptation, which reduces disaster risks to capital in the interim. Mitigation depends on belief regarding the adverse consequences of global warming. Pessimism jumps with a disaster and slowly reverts in the absence of arrivals. Mitigation spending by firms is less than first-best because of externalities. We prove that capital taxes to fund public mitigation, which requires collective action, restores first-best.

This paper aims to unpack the pro-social motivations of green innovators. In a field experiment inviting SBIR grantees to learn more about and apply to MIT Solve, we provide scientifically valid scenarios varying the time-frame and scale of human cost of climate change. Innovators' response in clicks and applications increases with both scale and immediacy treatments. Our structural model estimates a welfare discount rate of 0.76%, providing a measure of innovators' value of future generations, and an elasticity to lives lost of 0.23, implying diminishing marginal concern to human loss.

The authors propose that purchasing luxury can be a unique means to engage in sustainable consumption because high-end products are particularly durable. Six studies examine the sustainability of high-end products, investigate consumer decision making when considering high-end versus ordinary goods, and identify effective marketing strategies to emphasize product durability, an important and valued dimension of sustainable consumption.

Pricing greenhouse gas emissions involves making trade-offs between consumption today and unknown damages in the (distant) future. This setup calls for an optimal control model to determine the carbon dioxide (CO2) price. It also relies on society's willingness to substitute consumption across time and across uncertain states of nature, the forte of Epstein-Zin preference specifications.

Sustaining large-scale public goods requires individuals to make environmentally friendly decisions today to benefit future generations. Recent research suggests that second-order normative beliefs are more powerful predictors of behaviour than first-order personal beliefs. We explored the role that second-order normative beliefs — the belief that community members think that saving energy helps the environment — play in curbing energy use.

This article investigates the cost and feasibility of reducing U.S. greenhouse gas emissions by 80 percent from 2005 levels by 2050. The United States has stated in its Paris Conference of the Parties (COP) 21 submission that this is its aspiration. I suggest that this goal can be reached at a net cost in the range of $37 to $135 billion/year. I assume that the goal is to be reached by extensive use of solar photovoltaic and wind energy (66 percent of generating capacity), in which case the cost of energy storage will play a key role in the overall cost.

Until fairly recently, the main approach to getting business to respond to climate change has been top-down efforts to regulate emissions and enact various forms of "carbon pricing." The aim of such efforts has been to make businesses "internalize" the costs associated with greenhouse gas (GHG) emissions. Governments are expected to set the environmental protection rules for companies in their respective countries, and markets are expected to adjust to the new regulations and carbon prices.

I was thrilled to see thousands of activists and celebrities marching through Manhattan Sunday calling on the United Nations and government leaders to do more on climate change. Inaction by U.S. politicians is always at the epicenter of these calls, given Washington's lack of consensus on the issue. But this overlooks the track record of this country when it comes to reducing greenhouse gas emissions.