Evolution of Mortgage Lending


This memo details the types of entities involved in the mortgage origination space. Changes in the broader mortgage finance system from shocks, government regulations, interest rate fluctuations and other factors have led to this evolution in origination entities. The primary aim in this memo is to provide the reader with a sense of these shifts in lending origination entities since the Great Depression.

Subprime Lending

This memo explores the evolution of mortgage lending in the United States, with a particular focus on explicating the array of opaque, exotic, and increasingly complex mortgage instruments that emerged after the 1970s in tandem with the deregulation of American finance. The emergence of these mortgage types was one of many contributing factors to the housing bubble that set the stage for the 2008 financial crisis. After clarifying the most common features of subprime mortgages, the memo traces the historical evolution of American residential mortgages more generally, and exotic Adjustable Rate Mortgages in particular.


This timeline provides an overview of landmark federal and state regulations affecting the development of the mortgage market from the early 20th century to 2008. Legislation profiled ranges from foundational housing and consumer lending laws to anti-predatory lending laws. Descriptions focus on intended effects on the mortgage lending industry.


This memo describes how mortgages underwriting practices have evolved in the United States over the last century. The research covers the actors who have a bearing on underwriting practices, how technology has changed underwriting standards and practices, and how views around risk and major events have impacted underwriting.