The history of the Roman economy covers the period of the Roman Republic and the Roman Empire. Recent research has led to a positive reevaluation of the size and sophistication of the Roman economy.Moses Finley was the chief proponent of the primitivist view that the Roman economy was ""underdeveloped and underachieving,"" characterized by subsistence agriculture; urban centres that consumed more than they produced in terms of trade and industry; low-status artisans; slowly developing technology; and a ""lack of economic rationality."" Current views are more complex. Territorial conquests permitted a large-scale reorganization of land use that resulted in agricultural surplus and specialization, particularly in north Africa. Some cities were known for particular industries or commercial activities, and the scale of building in urban areas indicates a significant construction industry. Papyri preserve complex accounting methods that suggest elements of economic rationalism, and the Empire was highly monetized. Although the means of communication and transport were limited in antiquity, transportation in the 1st and 2nd centuries expanded greatly, and trade routes connected regional economies. The supply contracts for the army, which pervaded every part of the Empire, drew on local suppliers near the base (castrum), throughout the province, and across provincial borders. The Empire is perhaps best thought of as a network of regional economies, based on a form of ""political capitalism"" in which the state monitored and regulated commerce to assure its own revenues. Economic growth, though not comparable to modern economies, was greater than that of most other societies prior to industrialization.Socially, economic dynamism opened up one of the avenues of social mobility in the Roman Empire. Social advancement was thus not dependent solely on birth, patronage, good luck, or even extraordinary ability. Although aristocratic values permeated traditional elite society, a strong tendency toward plutocracy is indicated by the wealth requirements for census rank. Prestige could be obtained through investing one's wealth in ways that advertised it appropriately: grand country estates or townhouses, durable luxury items such as jewels and silverware, public entertainments, funerary monuments for family members or coworkers, and religious dedications such as altars. Guilds (collegia) and corporations (corpora) provided support for individuals to succeed through networking, sharing sound business practices, and a willingness to work.