What about top civil servants and other senior government officials? An investigation on that will definitely yield juicy information.
Anyway, assets declarations is good for public officials in a country where corruption scandals, imaginary or true, sell enormous quantities of newspapers and kick TV and radio ratings sky high. The risks of any top government official not declaring his or her assets are just too much because they can be easy prey for unscrupulous political opponents and their media hit men and women.
Declarations of assets are also a good thing for the image of any government as a collective entity because when people know about the assets of members of a government it will be extremely difficult for any political foe or unscrupulous journalist to tarnish the image of that government with false accusations of corruption.
A declaration of assets widely available to the public, including the ordinary man and woman, the rural farmer and urban small business owner, is indeed very good insurance against political or media impropriety.