William was very unlikely to become Catholic or pro-French which eliminated many tensions. Also, William very much needed Parliament's support for his war against France; however, the change in credibility argued by North and Weingast (1989) looks past William's reign, so it also requires confidence that William's successors would abide by the constitution. A source of long-run confidence was that the Glorious Revolution reasserted the risk of a monarch losing his throne. William III's decision tree in 1689 again looked like Charles II's in 1660, and Parliament's threat to remove an offending monarch was becoming credible. The seventeenth century had now seen Parliament remove two of the four Stuart monarchs, and the second displacement in 1688 was much easier than the wars that ended the reign of Charles I in 1649.Another lasting change that made the new constitution more credible than the old constitution was that William and his successors were more constrained in fiscal matters. Parliament's growing ‘power of the purse' gave the king less freedom to maneuver a constitutional challenge. Moreover, Parliament's fiscal control increased over time because the new constitution favored Parliament in the constitutional renegotiations that accompanied each succeeding monarch. As a result, the Glorious Revolution constitution made credible the enduring ascendancy of Parliament. In terms of the king, the new constitution increased the credibility of the proposition that kings would not usurp Parliament.
The second credibility story of the Glorious Revolution was that the increased credibility of the government's constitutional structure translated into an increased credibility for the government's commitments. A king who lives within the constitution has less desire to renege on his commitments. Recall that Charles II defaulted on his debts in an attempt to subvert the constitution, and, in contrast, Parliament after the Glorious Revolution generously financed wars for monarchs who abided by the constitution. An irony of the Glorious Revolution is that monarchs who accepted constitutional constraints gained more resources than their absolutist forebears.Still, should a monarch want to have his government renege, Parliament will not always agree, and a stable constitution assures a Parliamentary veto. The two houses of Parliament, Commons and Lords, creates more veto opportunities, and the chances of a policy change decrease with more veto opportunities if the king and the two houses have different interests (Weingast 1997).Another aspect of Parliament is the role of political parties. For veto opportunities to block change, opponents need only to control one veto, and here the coalition aspect of parties was important. An additional reason for Parliament's credibility was reputation. As a deterrent against violating commitments today, reputation relies on penalties felt tomorrow, so reputation often does not deter those overly focused on the present. A desperate king is a common example. As collective bodies of indefinite life, however, Parliament and political parties have longer time horizons than an individual, so reputation has better chance of fostering credibility.