ESG stands for Environmental, Social, and Governance, a framework used to evaluate how companies handle issues beyond their balance sheets. Investors, fund managers, and analysts use ESG criteria to screen companies based on their environmental impact, treatment of workers and communities, and leadership practices. The idea is straightforward: companies that manage these risks well may be better long-term investments, and investors increasingly want their money aligned with their values.
The Three Pillars of ESG
Each letter in ESG represents a distinct category of non-financial factors. Together, they paint a picture of how a company operates beyond quarterly earnings.
Environmental
Environmental criteria measure how a company affects the natural world and how it manages environmental risks. This includes greenhouse gas emissions (both direct and indirect), energy consumption, waste management, pollution controls, water usage, and natural resource conservation. Investors look at whether a company uses renewable energy, how it handles toxic waste, and whether it complies with environmental regulations. A manufacturing company that has reduced its carbon footprint and eliminated hazardous runoff would score well here. An oil company facing repeated spill violations would not.
Social
Social criteria focus on a company’s relationships with people: employees, suppliers, customers, and the communities where it operates. This covers fair wages, workplace health and safety, diversity and inclusion, ethical supply chain management, and community engagement. Analysts might look at whether a company pays living wages across its supply chain, offers safe working conditions, or contributes to local communities through charitable giving or volunteer programs. Labor disputes, discriminatory practices, or customer data breaches would hurt a company’s social score.
Governance
Governance examines the people running the company and the systems that hold them accountable. Key factors include board diversity, executive compensation, transparent accounting methods, shareholder rights, and internal controls. Investors want to see that a company avoids conflicts of interest in selecting board members and executives, doesn’t use political contributions to gain preferential treatment, and maintains honest financial reporting. Poor governance, like a board stacked with insiders or a CEO whose pay is wildly disconnected from company performance, signals risk.
How Companies Get ESG Scores
Several major rating agencies assess companies on ESG factors, and their methodologies vary significantly. S&P Global, one of the largest providers, scores companies on a scale of 0 to 100. Their process uses 62 industry-specific questionnaires sent directly to companies, requesting detailed data and supporting documentation beyond what’s publicly available. Companies that don’t respond still get scored: a team of analysts fills out the assessment using publicly available information.
The depth of analysis is considerable. S&P Global evaluates an average of 120 questions per company, drawing on up to 1,000 individual data points. Beyond annual assessments, companies are continuously monitored through media screening for controversies. The underlying metrics are weighted differently depending on the industry, since a tech company’s most important ESG risks differ from those of a mining operation. This approach, called materiality weighting, means two companies in different sectors could score well for very different reasons.
Other major rating providers include MSCI, Sustainalytics, and Bloomberg, each with its own scoring methodology. This is one of the framework’s biggest complications: a company might earn a high score from one agency and a middling score from another, because each provider weights and measures factors differently.
How Investors Use ESG
ESG criteria show up in investing in several ways. Some investors use negative screening, excluding entire industries from their portfolios. For example, the investment firm Trillium won’t invest in companies that earn 5% or more of revenue from coal mining, hard rock mining, gambling, tobacco, private prisons, or weapons manufacturing. Others use positive screening, actively seeking companies with the strongest ESG profiles in each sector.
A third approach integrates ESG factors into traditional financial analysis without automatically excluding any industry. Under this model, a fund manager might still invest in an energy company, but only one demonstrating strong environmental management relative to its peers. Many large institutional investors, including pension funds and university endowments, now incorporate some form of ESG analysis into their decision-making.
For individual investors, ESG typically enters the picture through mutual funds and exchange-traded funds (ETFs) labeled as sustainable, responsible, or ESG-focused. These funds apply their own screening criteria, so the specific companies included can vary widely from one fund to the next.
Does ESG Affect Financial Performance?
Research on the link between ESG and financial returns is extensive, though not unanimous. A study published in ScienceDirect found that a company’s overall ESG score was positively and significantly associated with both firm value and profitability. Breaking it down by pillar, social and governance scores showed a positive, significant relationship with firm value, while environment scores correlated with profitability but not as strongly with market value on their own.
The practical argument is intuitive: a company that manages environmental liabilities, treats workers well, and maintains transparent governance is less likely to face lawsuits, regulatory fines, boycotts, or scandals that destroy shareholder value. ESG advocates frame it less as a sacrifice and more as a form of risk management that happens to align with broader societal goals.
Criticisms and Limitations
ESG has attracted significant pushback from multiple directions. One major criticism is greenwashing, where companies or investment funds exaggerate their environmental credentials, portraying products or policies as producing positive outcomes when they don’t. This can happen at the corporate level, with companies misrepresenting their sustainability footprints or transition plans, and at the fund level, where a product marketed as “green” may hold companies that don’t meet most people’s definition of the term.
Some critics argue that ESG investing creates a tension with fiduciary duty, the legal obligation fund managers have to act in the best financial interest of their clients. If an ESG screen excludes a high-performing company, is the fund manager prioritizing values over returns? Others contend that ESG is a distraction from more effective policy solutions like carbon taxes, which would change corporate behavior through regulation rather than voluntary frameworks.
The lack of standardized reporting is another weak point. Without uniform rules for what companies must disclose, ESG ratings rely heavily on self-reported data and vary across rating agencies. The SEC adopted climate-related disclosure rules in March 2024 that would have required public companies to report on climate risks and greenhouse gas emissions, but the agency voted in 2025 to stop defending those rules in court, leaving the regulatory landscape uncertain.
Political backlash has also intensified, with some state governments restricting public pension funds from using ESG criteria, arguing it politicizes investment decisions. Meanwhile, other jurisdictions have moved in the opposite direction, requiring greater sustainability disclosure from companies operating within their borders.
What ESG Means for Everyday Investors
If you’re considering ESG in your own portfolio, the most important thing to understand is that “ESG” is not a single standard. Two funds with ESG in their name can hold very different companies and apply very different screens. Before investing, read the fund’s prospectus or methodology document to understand what criteria it actually uses, what industries it excludes, and how it defines terms like “sustainable” or “responsible.”
Fees matter too. Some ESG-focused funds charge higher expense ratios than comparable index funds, though the gap has narrowed as the market has grown more competitive. Compare the expense ratio of any ESG fund against a broad-market alternative to see what the premium looks like in dollar terms over the time horizon you plan to invest.
ESG is not a guarantee of ethical investing or superior returns. It’s a lens, one that adds non-financial factors to the evaluation of a company’s long-term prospects. Whether that lens is useful depends on what you’re trying to achieve and how much scrutiny you apply to the specific products available to you.