Large Language Models as Tax Attorneys: A Case Study in Legal
  Capabilities Emergence
Authors: name: John J. Nay, name: David Karamardian, name: Sarah B. Lawsky, name: Wenting Tao, name: Meghana Bhat, name: Raghav Jain, name: Aaron Travis Lee, name: Jonathan H. Choi, name: Jungo Kasai

Better understanding of Large Language Models' (LLMs) legal analysis
abilities can contribute to improving the efficiency of legal services,
governing artificial intelligence, and leveraging LLMs to identify
inconsistencies in law. This paper explores LLM capabilities in applying tax
law. We choose this area of law because it has a structure that allows us to
set up automated validation pipelines across thousands of examples, requires
logical reasoning and maths skills, and enables us to test LLM capabilities in
a manner relevant to real-world economic lives of citizens and companies. Our
experiments demonstrate emerging legal understanding capabilities, with
improved performance in each subsequent OpenAI model release. We experiment
with retrieving and utilising the relevant legal authority to assess the impact
of providing additional legal context to LLMs. Few-shot prompting, presenting
examples of question-answer pairs, is also found to significantly enhance the
performance of the most advanced model, GPT-4. The findings indicate that LLMs,
particularly when combined with prompting enhancements and the correct legal
texts, can perform at high levels of accuracy but not yet at expert tax lawyer
levels. As LLMs continue to advance, their ability to reason about law
autonomously could have significant implications for the legal profession and
AI governance.