Summary: GAO discussed: (1) the purposes and general activities of government-sponsored enterprises (GSE); (2) risks GSE and the government face from failure; and (3) the need for appropriate oversight and capital standards for GSE. GAO noted that: (1) there were no indications suggesting immediate failure of GSE; (2) it did not conduct an independent test of the financial vulnerabilities of GSE; (3) the government protects some GSE investments through federal oversight, including monitoring, enforcing reasonable practices, and implementing reasonable capital standards; (4) a close tie between the government and three GSE weakened the discipline that creditors normally provide to private firms; and (5) a lack of appropriate federal or private discipline for those GSE made the federal government vulnerable to losses from any serious future GSE problems. GAO believes that the government needs to implement a better oversight system, reasonable risk-based capital rules, and appropriate enforcement authorities for three GSE.