Financial systems are especially vulnerable to political instability. Under instability, governments and factions aspiring to be governments have strong incentives to steal bank reserves, force financial institutions to make them loans, engage in the unrestrained printing of currency (thereby setting off an inflationary tax on holding cash), and change the rules that regulate banking and the securities markets to maximize the government's access to funds.

The Mexican financial system was indeed negatively affected by political instability but only in the short run. The fight against Huerta in 1913–14 and the ensuing civil war among the victors from 1914 to 1917 brought about a near total collapse of the banking system. The governments that came to power after 1917, however, regardless of their stated ideologies, all recognized the need to accommodate the bankers. These governments understood that they needed a source of credit in order to restore political order. They also understood that without a functioning financial system there could be no economic growth, and without economic growth there would be no tax revenues. In short, the post-1917 governments realized that restoring the financial system was crucial to their own political survival.

The Obregón and Calles governments therefore recreated the vertical political integration (VPI) arrangements that underpinned banking during the Porfiriato. Just as Díaz had done, they selectively enforced property rights and allowed the bankers themselves to write the laws regarding entry into banking.