Ozment, Steven E. The Age of Reform: 1250-1550 : An Intellectual and Religious History of Late Medieval and Reformation Europe. New Haven, Conn. ; London: Yale University Press, 1980. Kindle Electronic Edition.
Chapter 5, “On the Eve of the Reformation” pp. 182-222. Part 2, “Population, Money, and Books” pp. 190-203.
At the same time that Europe was changing politically it was also recovering in population after the 14th century famines and plagues. This growth stabilized by about 1600 (Ozment 1980, 191). “The later Middle Ages also saw the development of a money economy” (Ozment 1980, 192). In the new, more centralized, states, rulers would impose more taxes, provoking revolts (Ozment 1980, 194).
“Like secular rulers, popes also adjusted to the new money economy and found themselves internally transformed by it” (Ozment 1980, 195). Among other things, popes would reserve the right to fill vacant offices, doing so when payment of a fee was received.
The period leading up to the Reformation was also a time of inflation. Ozment describes (Ozment 1980, 199) how inflation was probably caused by the increase in population, creating a greater demand for goods. Among those goods, the rise of printed books revolutionized communication and publications. Between 1460 and 1500 more books were produced than through the whole of the Middle Ages (Ozment 1980, 199) Corresponding to this, colleges and universities multiplied (Ozment 1980, 201) as the society at large became better educated.