In modern credit-based economies, deflation may be caused by the central bank "initiating" higher interest rates (i.e., to 'control' inflation), thereby possibly popping an asset bubble. In a credit-based economy, a slow-down or fall in lending leads to less money in circulation, with a further sharp fall in money supply as confidence reduces and velocity weakens, with a consequent sharp fall-off in demand for employment or goods. The fall in demand causes a fall in prices as a supply glut develops. This becomes a deflationary spiral when prices fall below the costs of financing production, or repaying debt levels incurred at the prior price level. Businesses, unable to make enough profit no matter how low they set prices, are then liquidated. Banks get assets that have fallen dramatically in value since their mortgage loan was made, and if they sell those assets, they further glut supply, which only exacerbates the situation. To slow or halt the deflationary spiral, banks will often withhold collecting on non-performing loans (as in Japan, and most recently America and Spain). This is often no more than a stop-gap measure, because they must then restrict credit, since they do not have money to lend, which further reduces demand, and so on.