W.C. Bunting and Tomer Stein investigate the role of amicus curiae process in the development of business law cases at the state level. The findings reveal that the business law amicus curiae process is dominated by lobbying groups, particularly by associations serving big business, and that these “Amicus Lobbying” efforts have a higher success rate compared to non-lobbying groups.

Business law litigation does not only impact the parties standing in front of the court, it also sets a precedent that changes the economy and the markets. But while the impact of precedent is general, only those directly impacted by the underlying dispute have a right to plead their case in court. 

To address this mismatch between impact and access, the amicus curiae filing process was born. Amicus curiae, or “friends of the court,” is a process that allows those with stakes in the precedent set by the ligation to express their opinion on the legal question at hand. In theory, amicus curiae filings are beneficial for all parties because they provide the courts with expertise about subject matters that the litigants may not provide and representation by stakeholders who are not otherwise party to the litigation. But do they really provide these benefits? 

We empirically tested the amicus curiae process in business law, on the state level, and revealed that there are serious reasons to doubt that it is an unbiased source of expertise and representation. We find that the business law amicus curiae process is dominated by lobbying groups, and that these “Amicus Lobbying” efforts have an outsize success rate.   

Construction of Dataset

Investigating the amicus curiae process first required the construction of a unique dataset, comprising amicus filings in five states that represent providers of particularly impactful business law precedent: New York, California, Delaware, Texas, and Nevada. To consistently limit the subject matter and timeframe of these data, we only collected business law amicus filings from 2005 to 2022 that fall under the following business law categories: contracts, business torts and products liability, insurance, consumer law, corporate law, business associations, mergers and acquisitions, commercial law, antitrust, banking and finance (including negotiable instruments), securities regulation, real property (including landlord-tenant law), debtor—creditor law, and bankruptcy and reorganization law.

One of the main contributions of this study is assembling the only dataset of amicus curiae briefs in business law. While other scholars have focused on how, and to what extent, non-parties participate in the United States Supreme Court’s decision-making process through the submission of amicus curiae, this study is the first to examine the amicus curiae process in the narrower context of business law. Because many business law disputes take place at the state court level, this study focuses on state courts exclusively and does not analyze amicus curiae briefs filed in federal courts. Collecting amicus curiae briefs filed in state courts, however, is not straightforward. Unlike the U.S. Supreme Court, state courts have not created online electronic dockets that allow for easy search for amicus curiae briefs, nor have the main legal research services themselves set up their databases to allow for a search by amicus curiae briefs specifically.  As a result, to create this dataset, we had to individually hand-collect amicus curiae briefs.

Empirical Findings

Our study uses this hand-collected dataset to present two key empirical findings related to        (1) the prevalence of Amicus Lobbying, and (2) the success rates of Amicus Lobbying.

Prevalence of Amicus Lobbying

The first question that we sought to answer is whether the business law amicus curiae process represents a diverse set of stakeholders distributed across various socioeconomic positions or, rather, is it controlled by a defined set of repeat players. To help answer this question, Table 1 displays the distribution of amicus curiae briefs by filer category.

Table 1: Amicus Briefs by Filer Category

Filer CategoryFrequencyPercentage
Lobbying Group76166.9%
Individual (non-professor)655.7%
Government Agency564.9%
Individual (professor)524.6%
Union3< 0.1%

Strikingly, Table 1 demonstrates that lobbying groups dominate the business law amicus curiae process. Approximately 67% of all amicus briefs in our dataset were filed by lobbying groups. Amicus briefs filed by individuals, on the other hand, which includes both professors and non-professors, accounted for only about10% of all amicus curiae filings. 

What is a lobbying group? In this study, a lobbying group is defined to include any group whose main purpose is to promote or defend a well-defined set of legal or policy positions and includes both: (1) a business association (or trade association), and (2) a public interest advocacy group. A business association (or trade association) is defined as any group that is founded or funded by, or for, companies operating in a specific industry, but that does not engage in operative business themselves. Examples include the U.S. Chamber of Commerce, the American Insurance Association, and the Product Liability Advisory Council. A public interest advocacy group, by contrast, is defined as any group that exists primarily to promote a common good that extends beyond the narrow economic self-interests of its members or supporters. Examples here include the United Policyholders, the Consumer Attorneys of California, the National Consumer Law Center, and the Washington Legal Foundation. Table 2 displays the distribution of lobbying groups by category type.

Table 2: Lobbying Groups by Category Type

Lobbying Group TypeFrequencyPercentage
Business Association/Trade Association55873.3%
Public Interest Advocacy Group20326.7%

Notably, almost three-quarters of amicus curiae briefs by lobbying groups were filed by business associations (or trade associations) as opposed to public interest advocacy groups. This empirical finding supports the view that organized groups in society with greater financial resources at their disposal can more frequently influence the decision-making processes of government, including the judicial branch.    

To identify the lobbying groups driving this amicus filing activity, Table 3 lists the top ten lobbying groups in terms of the number of amicus briefs filed during our study period.

Table 3.  Top 10 Lobbying Groups

U.S. Chamber of Commerce77
American Insurance Association33
United Policyholders31
Complex Insurance Claims Litigation Association22
Product Liability Advisory Council20
Consumer Attorneys of California20
National Association of Manufacturers19
Civil Justice Association of California18
California Bankers Association15
Texas Civil Justice League14

Table 3 suggests that the business law amicus curiae process is controlled by a defined set of repeat players. Representing more than five percent of the amicus briefs in our dataset, for example, the U.S. Chamber of Commerce filed the most amicus curiae briefs—more than two times the number of the next highest filer.

Success Rate by Lobbying Groups

Having found that amicus lobbying is a main driver of amicus filing activity in state court business law cases, the second question that we sought to answer is whether the lobbying groups that dominate this channel of influence can use this activity to obtain a litigation advantage. To answer this question, we examine whether having a lobbying group file an amicus curiae brief increases the probability of a successful disposition of the case. Table 4 compares the success rates for lobbying groups and non-lobbying groups, respectively.

Table 4. Success Rate by Lobbying Group

Lobbying StatusSuccessful DispositionFrequencyPercentage
Non-Lobbying GroupsNo15150.5%
Lobbying GroupsNo26244.1%

Significantly, Table 4 shows that cases in which a lobbying group files an amicus brief are resolved favorably nearly 56% of the time, which is about 6.5 percentage points higher than the success rate in cases where a non-lobbying group files an amicus brief. A regression analysis confirms that this 6.5-percentage point difference is statistically significant. This difference in success rates suggests that lobbying groups not only dominate the business law amicus curiae process, but that they are good at it as well.  While this success is likely attributable to several different causal factors, the repeated participation of lobbying groups in the business law amicus curiae process highlighted in Table 1 suggests that these groups have had the opportunity to develop and hone, over time, a relative legal expertise in this form of shadow influence over the judiciary that can be provided to their clients at a lucrative price. Policy Implications

Generally, the amicus curiae process can provide the courts with two related yet distinct benefits: (1) Representation—the amicus process can allow the courts the ability to hear voices with stakes in the litigation that would otherwise not have access to the litigation; and (2) Expertise—amicus filers can provide the courts with expertise they do not possess or have access to. Because the business law amicus curiae process, however, is dominated by Amicus Lobbying efforts, it is unlikely that representation and expertise are being adequately served. There simply is a lack of competitiveness in the flow of non-litigant legal opinions to the judiciary, resulting in a biased set of well-funded legal positions.   

We, therefore, suggest two solutions to the problem of amicus lobbying in business law. First, we suggest a federalization of the business law amicus curiae process that establishes uniformity, disclosure of filings and interest in the litigation, and a centralized and publicly available dataset of these filings. This will provide transparency to the—but for our study—shadow practice of lobbying, which has largely evaded the public eye. Second, we suggest state and local law initiatives that would require, in certain important legal disputes of first impression, the subsidization of amicus curiae filings by stakeholders who would not otherwise be able to organize and pay for such a legal service. 

Articles represent the opinions of their writers, not necessarily those of the University of Chicago, the Booth School of Business, or its faculty.