Sarah E. Light

Sarah E. Light
  • Mitchell J. Blutt and Margo Krody Blutt Presidential Professor
  • Professor of Legal Studies & Business Ethics

Contact Information

  • office Address:

    Jon M. Huntsman Hall, Suite 600
    3730 Walnut Street
    Philadelphia, PA 19104

Research Interests: Climate law and policy, environmental law and policy, private environmental governance

Links: CV, Wharton Climate Center, Penn Program on Regulation


Professor Light’s research examines issues at the intersection of environmental law, corporate sustainability, and business innovation. Her articles have addressed the ways in which laws that structure corporations and the marketplace should be considered forms of environmental law; how private actions by business firms, such as the adoption of a private carbon fee, or lending and underwriting decisions by banks and insurance companies, can be forms of private environmental governance; and how to address concerns about greenwashing consistent with the First Amendment.  Her articles have appeared in the Stanford Law Review, the Columbia Law Review, the Duke Law Journal, the UCLA Law Review, and the University of Pennsylvania Law Review, among others.

Professor Light serves as Faculty Co-Director of Wharton’s Climate Center.

Professor Light has repeatedly been awarded Wharton Teaching Excellence Awards in both the undergraduate and MBA divisions.


JD, Yale Law School, 2000

M. Phil, Politics, Oxford University (Rhodes Scholar), 1997

A.B., Social Studies, Magna Cum Laude, Harvard University, 1995

Academic Positions Held

The Wharton School:

Professor of Legal Studies and Business Ethics, 2023-present.

Associate Professor of Legal Studies and Business Ethics (with tenure), 2019-2023.

Assistant Professor, 2013-2019.

Princeton University, Law and Public Affairs Fellow, 2019-2020.

Previous appointments: Columbia University, Lecturer; Brooklyn Law School, Visiting Assistant Professor; Fordham Law School, Adjunct Associate Professor.

Other Positions

Assistant United States Attorney for the Southern District of New York, Civil Division, 2001-2011.

Chief, Environmental Protection Unit, United States Attorney’s Office for the Southern District of New York, Civil Division, 2007-2011.

Law Clerk, Honorable John M. Walker, Jr., Court of Appeals for the Second Circuit, 2000-2001.

Pro Bono

Pro Bono Mediator, United States District Court for the Southern District of New York.

Pro Bono Mediator, New York Peace Institute.

Continue Reading


  • Amanda Shanor and Sarah E. Light (2022), Greenwashing and the First Amendment, Columbia Law Review, 122 (), pp. 2033-2118.

    Abstract: Recent explosive growth in environmental and climate-related marketing claims by business firms has raised concerns about their truthfulness. Critics argue (or at least question whether) such claims constitute greenwashing, which refers to a set of deceptive marketing practices in which an entity publicly misrepresents or exaggerates the positive environmental impact of a product, service, or the entity itself. The extent to which greenwashing can be regulated consistent with the First Amendment raises thorny doctrinal questions that have bedeviled both courts and scholars, the answers to which have implications far beyond environmental marketing claims. This Essay is the first to offer both doctrinal clarity and a normative approach to understanding how the First Amendment should tackle issues at the nexus of science, politics, and markets. It contends that the analysis should be driven by the normative values underlying the protection of speech under the First Amendment in the disparate doctrines that govern these three arenas. When listeners are epistemically dependent for information on commercial speakers, regulation of such speech for truthfulness is consistent with the First Amendment and subject to the laxer review of the commercial speech doctrine. This is because citizens must have accurate information not only to knowledgeably participate at the ballot box but also to have meaningful freedom in economic life itself.

  • Sarah E. Light and Christina Skinner (2021), Banks and Climate Governance, Columbia Law Review, 121 (), pp. 1895-1956.

    Abstract: Major banks in the United States and globally have begun to assert an active role in the transition to a low-carbon economy and the reduction of climate risk through private environmental and climate governance. This Essay situates these actions within historical and economic contexts: It explains how the legal foundations of banks’ sense of social purpose intersect with their economic incentives to finance major structural tran­sitions in society. In doing so, this Essay sheds light on the reasons why we can expect banks to be at the center of this contemporary transition. This Essay then considers how banks have taken up this role to date. It proposes a novel taxonomy of the various forms of private environmental and climate governance emerging in the U.S. banking sector today. Fi­nally, this Essay offers a set of factors against which to normatively assess the value of these actions. While many scholars have focused on the role of shareholders and equity in private environmental and climate govern­ance, this Essay is the first to position these steps taken by banks within that larger context.

  • Sarah E. Light (2020), National Parks, Incorporated, University of Pennsylvania Law Review, 169 (), pp. 33-109.

    Abstract: Public lands and private enterprise exist in an uncomfortable equilibrium. Since their founding, the national parks have embraced some forms of private enterprise, including privately-run accommodations, to bring members of the public to the parks to enjoy and appreciate their beauty. Corporations have provided financial support to the national parks through philanthropy. And private firms have benefitted from marketing their associations with the parks. Marketing campaigns that call on the feeling of being in the woods and philanthropy to the parks that may benefit corporations by association do not deplete resources or ruin aesthetic experiences like a strip mine would. Yet they nonetheless in some fashion dilute the essential publicness of the national parks. In debates over the purpose of public lands and the proper role of private enterprise within them, relationships between private firms and public lands in which the firms neither extract commodities from the parks nor physically harm them have not received sufficient attention. This Article makes three claims. First, as a descriptive matter, it identifies a set of non-extractive relationships between private firms and national parks as a distinct phenomenon. Second, as a normative matter, the Article argues that these relationships deserve greater attention in both policy and scholarship because they shed light on important questions about the significance of the public in national parks. Finally, as a prescriptive matter, the Article concludes that these non-extractive relationships between private firms and the national parks warrant clearer restrictions in government policy to preserve the essential publicness of these lands.

  • Sarah E. Light and Carolyn Kousky (2019), Insuring Nature, Duke Law Journal, 69 (), pp. 323-376.

  • Sarah E. Light (2019), The Role of Universities in Private Environmental Governance Experimentalism, Organization & Environment, 34 (), pp. 466-483.

  • Sarah E. Light (2019), The Law of the Corporation as Environmental Law, Stanford Law Review, 71 (1).

  • Sarah E. Light (2018), Regulatory Horcruxes, Duke Law Journal, 67 (8/2).

  • Sarah E. Light, The Role of the Federal Government in Regulating the Sharing Economy. In Cambridge Handbook on the Law of the Sharing Economy, edited by Nestor Davidson, Michèle Finck, and John Infranca, (Cambridge Univ. Press, 2018), (:, 2018)

  • Eric Biber, Sarah E. Light, J. B. Ruhl, James Salzman (2017), Regulating Business Innovation as Policy Disruption: From the Model T to Airbnb, Vanderbilt Law Review, 70 (5), pp. 1561-1626.

  • Sarah E. Light (2017), Advisory Nonpreemption, Washington University Law Review, 95 (2), pp. 325-383.


Environmental Management: Law and Policy: LGST 2150/8150 Syllabus (Fall 2022):

Business, Social Responsibility, and the Environment: LGST 6130 Syllabus (Fall 2022):

Climate and Environmental Leadership in Action: LGST 2600 (formerly LGST 299) (Spring 2022):

Negotiations: LGST 8060 Syllabus (Fall 2021):


Awards and Honors

  • Penn Fellows Program, 2023-2024
  • Wharton Teaching Excellence Award (Undergraduate Program), 2021
  • Wharton Teaching Excellence Award (MBA Program), 2021
  • Winning Article, Land Use and Environment Law Review, The Law of the Corporation as Environmental Law, 2020 Description

    Annual peer-selected compendium of leading articles in environmental law.

  • Top 20 Article, Environmental Law & Policy Annual Review, Insuring Nature, 2020 Description

    Annual compendium of the year’s “best environmental law or policy ideas” in the legal academic literature.

  • Wharton Teaching Excellence Award, 2019
  • Wharton Teaching Excellence Award, 2018
  • Trustees’ Council of Penn Women’s 25th Anniversary Award for Excellence in Advising, 2019
  • Winner, Alliance for Research on Corporate Sustainability (ARCS) Emerging Sustainability Scholar Award, 2018 Description

    The ARCS Emerging Sustainability Scholar Award recognizes a scholar in the area of corporate sustainability who is likely
    to make significant contributions to the advancement of corporate sustainability scholarship. The award will be granted
    in recognition of a scholar’s existing body of research and in anticipation of the scholar’s research trajectory. The
    selection committee will look for candidates with rigorous and salient contributions that cross disciplinary and national

  • Honorable Mention, Environmental Law & Policy Annual Review, Precautionary Federalism and the Sharing Economy, 2017 Description

    Sarah E. Light, Precautionary Federalism and the Sharing Economy, 66 Emory L.J. 333 (2017) was selected for Honorable Mention by the Environmental Law and Policy Annual Review, a joint publication of the Environmental Law Institute and Vanderbilt Law School. The article was selected as one of the seven “best environmental law or policy ideas” from a pool of “hundreds of law journal articles on environmental topics published between August 2016-and July 2017” by “environmental leaders from the academy as well as the public and private sectors.”

  • Winning article, Land Use and Environment Law Review, Parallels in Public and Private Environmental Governance, 2017 Description

    Annual peer-selected compendium of leading articles in environmental law.

  • Excellence in Teaching Award in the MBA Program, 2017
  • Academy of Legal Studies in Business Outstanding Proceedings Paper, for Precautionary Federalism and the Sharing Economy, 2016
  • People’s Choice Award, Alliance for Research on Corporate Sustainability (ARCS), for Precautionary Federalism and the Sharing Economy, 2016
  • One of ten faculty nominated by the MBA student body for the Helen Kardon Moss Anvil Award, 2016 Description

    The Helen Kardon Moss Anvil Award is awarded annually at Commencement to the one faculty member "who has exemplified outstanding teaching quality during the last year." A list of nominees is generated through a vote by MBA students and nominations from academic departments. The Anvil Award Selection Committee, comprised of student leaders, administrators and past Anvil Award winners, selects the recipient.

  • Environmental Law and Policy Annual Review, Winning Article, 2015 Description

    Sarah E. Light, The Military-Environmental Complex, 55 B.C. L. Rev. 879 (2014) was selected as one of the year’s “best law and policy-relevant ideas on the environment from the legal academic literature,” (one of four winners selected from over 400 articles), with abridged version reprinted in the Environmental Law & Policy Annual Review (2015).

  • Haub Environmental Law Distinguished Junior Scholar, 2015 Description

    The Haub Environmental Law Distinguished Junior Scholar Award is presented annually to an emerging junior environmental law professor who exhibits scholarly excellence and promise at an early stage in his/her career. The Haub School invites the award recipient to present his/her recent scholarship to the Haub community. The Haub Environmental Law Faculty solicits nominations from law professors throughout the country and selects a recipient from that pool of nominations.

  • Penn Fellows Program, 2023-2024

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