A regional economic history of Thailand is important for a broad picture of the economic changes in the country for a number of reasons. First, most existing studies focus to a large extent on Bangkok and the economic progress of this city and the central areas. This is understandable. Bangkok itself, since its inception as Thailand's capital in 1782, has always been the most significant urban centre in Thailand — indeed, the only city of considerable size in the country until the very recent period. Thus, Bangkok has been the centre of court and government, manufacturing production, consumption, finance and foreign trade, and a host of other economic activities. This has naturally induced historians to look mainly at Bangkok for significant changes in the Thai economy, and to ignore what is happening in the rest of the country.

Again, there is a cultural dimension to Bangkok's centrality in the story of Thailand's economic development. Bangkok has traditionally been seen as the focus of social changes, and regional developments have been obscured by such an emphasis on the capital. Equally, many of the existing sources, whether records of government departments, newspapers, or descriptions by foreign travellers, all tend to pay attention primarily to Bangkok.

Of course, Bangkok is a major part of the story of Thai economic development, and in this study Bangkok is given a prime place as one of the important regions of Thailand. But we also emphasize changes in the other regions, give importance to the ways in which Bangkok had an impact on the other regions, as well as how changes in the other regions affected Bangkok.

Another reason for a regional approach to Thai development is that for much of the nineteenth and well into the twentieth century, the realities of communications and transport in Thailand meant the existence of quite separate regional economies. Certainly river transport linked many parts of the country, but away from the main river arteries, road transport was often non-existent and local specialization and regional commercial hubs were prevalent. Such regional economies often fall below the radar of studies whose focus is national rather than regional. We may reflect, for example, that until the close of the nineteenth century, links between the northern cities of Chiang Mai and Lampang were often more developed with Burma (through overland trade) than they were with Siam proper.