- Control money supply
- Prudential supervision of the banking/financial system
In performing these functions however, you tend to get three types of people (men in the main) who head up the Central Banks:
- Patron governors: These are in effect there to support the economic policies of the government of the day. So they'll adopt monetary policy and in some cases, supervisory policy to the govt's economic policies. As an example, in the US we had Greenspan who in support of credit-based economic growth adopted loose banking regulation (even going along witht the idea of awarding self-regulation to some of the larger ibs). In Kenya, we had men like Kortut who was very supportive of the export intiatives that Pattni had come up with or even Mullei who was able to relax the reserve ratio in 2003 so that banks could lend more. In Nigeria, Chukwuma Soludo presided over the introduction of margin lending which indirectly has brought the Nigerian banking system to needing bail-out.
- Clean-up governors: Patron governors with a few exceptions, always create a mess. Guaranteed. Because their policies are not rooted in the basic functions of a central bank, these types of governors wonder into unfamiliar territory which (a) they don't understand (b) can't not then control. Greenspan was talking about cleaning up the mess created by "irrational exburance", but he really didn't know or understand what he was talking about since the scale of the bailout has been huge. Clean up governors therefore have a thankless task of undoing the work of patron governors. Cheserem did this in Kenya in the mid 90s.
- Independent governors: In effect perform the function of a central bank and are thus usually quite unpopular only surviving due to a change of government. Mervyn King has done this to a certain extent. In Kenya, we are yet to see one but urgently need one.