This book, A Regional Economic History of Thailand, presents an economic history of Bangkok, the Central Region, the North, the South, and Northeastern Regions from the signing of the Bowring Treaty in 1855 to the present. It takes a regional perspective, which is meant to provide a more accurate picture of the long-term development of the country's infrastructure, economy and society than a Bangkok-centric approach. Although Bangkok has undeniably had a wide-ranging influence on Thai society, studying the economic history of all of the kingdom's regions at the same time yields a more complete picture of the changes in the Thai economy. Four reasons support this argument.

Firstly, past studies of the long-term economic changes in Thailand have focused primarily on Bangkok, its surrounding areas and the central delta region. This is because Bangkok is the capital city and centre of government, finance, commerce, industry, consumption, and international trade. It is the most populous city and exerts tremendous influence over the social, cultural, and economic development of other regions. Furthermore, research resources, such as government documents, newspapers, and foreign records of Thailand's history, most commonly originated from the capital. Most research has, therefore, focused on Bangkok as the centre of change affecting other regions and has neglected other regions that had an influence on Bangkok.

Secondly, the social and economic fundamentals of the five regions are inherently different and are unique to each region. These fundamentals include population (for example, ethnicity); economy; agriculture, industry and service infrastructure; and geography (plains, hills, mountains, seas). It is therefore important to study each region separately. Stark social and economic differences may exist even within the same region, such as in the eastern and western parts of the Central Region, so the distinct characteristics of each should also be explained. In contrast, almost all past studies of long-term economic changes (such as over a 100-year period) have addressed a particular area in isolation instead of examining the five regions together to compare factors such as geography, including an area's distance to a river or sea, and the availability of natural resources and raw materials.