Book excerpt: The first articles in this volume focus on sources for the history of Baltic commerce and the evaluation of their data on prices. In most cases, though, surviving data is hardly adequate for any extensive quantitative analysis of Polish economic history, and many of these articles endeavour in different ways to use comparitive approaches to help overcome this lack of substantial statistical base - hence the set of studies on the economy of travelling and the observations of travellers. Professor Maçzak then turns to the structures of power in Poland and elsewhere in late renaissance Europe, looking in particular at informal power relationships and patterns of patronage. In terms of the Polish-Lithunaian state, he would hold that centralized government was already critically weakened in the late 15th century, and the 16th century saw the creation of a new power structure, based on local self-government, and dominated by the nobility.