China's central bank has raised the cash reserve ratio by banks for the fourth time this year. The latest move, raising the required reserve ratio from 20% to a record 20.5%, is expected to lock up about 350 billion yuan or $54 billion that banks would otherwise be able to lend. By insisting banks hold more cash, the central bank hopes to restrict lending, which in turn will reduce spending. The Chinese central bank has also raised interest rates four times since October as it tries to curb inflation.