This paper compares the development and role of rural trade venues in Holland in the 13th, 14th and early 15th century to the situation in England and Flanders. Even though a growing body of research stresses the importance of markets for medieval economies, the timing and the extent of the commercialisation of the countryside are still subjects of debate. The idea that peasants were by nature subsistence-oriented and only turned to the market if they were forced to, has proved incorrect: the production of foodstuffs and raw materials for the market was an integral part of peasant agriculture. However the neo-classical alternative, of peasants always ready and even eager to engage in specialisation and market-oriented production, is not satisfactory either. It does not explain why in some situations peasants reacted to market opportunities with great alacrity, whereas at other times and in other places they were much more reluctant to do so. Institutional economics offer a fruitful approach to this paradox, by predicting that peasants respond to the institutional framework that shapes the functioning of markets. Where market institutions were efficient and transaction costs were low, peasants did produce for the market as soon as they found there was a demand for their products. But where markets were difficult to enter or unsafe, creating high barriers to trade, peasants chose for subsistence as the less costly or less risky alternative.