While visiting Beijing, China on Monday, President Obama announced a new plan to extend the length of visas for Chinese nationals. Under the new agreement, Chinese student visas would be expanded to five years while business and tourist visas would be expanded to ten years.
Currently, visas are granted on a year-at-a-time basis. By expanding the length of stay to as many as 10 years, travelers could develop roots in the United States possibly leading to visa overstays. The Pew Hispanic Center estimates that visa overstayers account for 40% of the illegal-alien population in the United States, and without a biometric entry/exit system, it's difficult for the United States to prevent visa overstays.
China currently has an 8.5% visa refusal rate, meaning 8.5% of all visa requests to enter the U.S. are denied. This rate is higher than that of most developed/developing countries. It can be attributed to the U.S. deeming that travelers are more likely to overstay their visa.
For more information on this story, read the article in USA Today