Misguided policies, a backlash over terrorism or a failure to integrate migrants could all cause serious problems.

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"Systemic risk" (the risk that the failure of one financial institution could cause other interconnected institutions to fail and harm the economy as a whole).

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The failure to pass a quick fix could cause a sharper correction in early 2013.

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Dependency on a single company is interesting when exploring the risks that a single instance of corporate mismanagement (or strategic failure, or organizational misfortune) could cause severe economic damage.

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And Syria's failure to maintain a cease-fire could cause enough frustration to shift the political landscape.

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The failure to file and pay self-employment tax by self-employed individuals could cause them to be ineligible for social security retirement or disability benefits.

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It's important to note, however, that Kadcyla is not the same as Herceptin and could cause serious side effects including liver problems and heart problems such as congestive heart failure or even death.

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In any case, the failure of one engine would be unlikely of itself to cause a crash, as a modern jet could keep flying with its second engine alone.

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They project that the failure to renew the wind production tax credit, which is set to expire on December 31, could cause the wind turbine market to contract by 80 percent, putting tens of thousands of jobs in jeopardy.

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