The book "The Ascent of Money" by Niall Ferguson discusses the historical context of financial regulations, particularly focusing on the rules established in 1966 under Regulation Q. This regulation set a cap on deposit interest rates, limiting them to 5.5 percent, which was slightly higher than what banks were permitted to offer their customers. This ceiling influenced the financial landscape and shaped how banks competed for deposits.

Ferguson's analysis highlights the impact of such regulations on the broader economy and the dynamics between different financial institutions. These restrictions on deposit rates led to various responses within the banking sector and affected how consumers managed their savings, illustrating the complex interplay between regulation and financial growth over time.