Chip shortage typically occurs when there is some sociological or physical change that prevents certain chips from being produced in large enough numbers to satisfy demand. A severe case of chip shortage occurred in 1988 after a pact between American and Japanese chip manufacturers resulted in severely reduced production. Changing to newer production methods also causes chip shortages as the new factories are not built quick enough to meet the demand for the newer chips. An example was the shortage of smart card chips in 1999, another was during the rationing of other types of chips in 2004. The 2011 Japanese earthquake led to a period when it was difficult to source all the parts needed for various systems.