The recent press coverage related to ties between a Mexican company with major public works contracts and the administration of President Enrique Pena Nieto demonstrates that public records are useful in many international research applications. In bringing to light the connections between the contractor and the Pena Nieto administration, investigative reporters used property records and financial disclosure statements to demonstrate that Mexico's finance minister, Luis Videgaray, purchased a home from a company owned by the contractor. The Wall Street Journal covered the story domestically.
In Mexico, government employees are required to disclose their assets electronically through the DeclaraNet system. Like other countries in the Americas, however, Mexico does not make all parts of a financial declaration public by default leaving some decisions about what will and will not be disclosed to the filer.
For more information on the availability of records internationally, check with Right2Info.org which does a phenomenal job of tracking international access to information laws. One recent example: Pakistan becomes the fourth country in the world to make tax records public.