As Washington debates how to fix America's immigration system, the time has come for realistic solutions that will both strengthen national security and boost economic growth.Business Roundtable, an association of CEOs of America's leading companies, believes immigration reform is essential for creating a more healthy U.S. economy.Overhauling our immigration system will place more resources toward enforcement; produce a more dynamic and skilled labor force; and enable U.S. businesses to compete more effectively in the global marketplace. Reform can help accelerate our economic recovery and, as a result, encourage hiring. Here's how:Business requires certainty -- a predictable environment in which to plan and make investment decisions.That means the law must be consistently enforced across the country, and legal immigration channels must function properly.Border controls and immigration law enforcement must be strengthened, and an employment verification system should ensure that each new worker is legally authorized to live and work here.The current federal system, E-Verify, has improved significantly in recent years, but is still a work in progress, vulnerable to fraud and identity theft.The federal government should bear the responsibility for maintaining the database behind this electronic system, making sure it's reliable, accurate and guards against fraud. Employers must bear the responsibility of checking every new hire in that system.Looking ahead, all Americans would benefit by welcoming those who would come here legally to work and contribute to our economy.Today, the visa system prevents many outstanding foreign-born scientists, engineers and other highly educated professionals from working in the United States. Faced with a shortage of temporary high-skilled visas and 6- to 10-year waits for employment-based green cards, foreign graduates of U.S. universities are taking their talents elsewhere. Wouldn't it better to have them working for us rather than for our foreign competitors?Consider that immigrants or the children of immigrants founded 40 percent of U.S. Fortune 500 companies. Almost 25 percent of engineering and technology companies founded in the United States from 2006 to 2012 had at least one foreign-born founder.Across America, these companies employed about 560,000 workers and generated $63 billion in sales in 2012.Our immigration system deprives the nation of too many young, educated hard-working people who can represent the best of America, our entrepreneurial spirit.At the same time, no workable legal visa exists for U.S. employers to fill jobs that are essential and do not require a high school degree -- like service personnel at hotels, restaurants and in other sectors.Despite high U.S. unemployment, for a variety of reasons these jobs may go unfilled as small businesses struggle to grow without these essential workers. Without practical visa programs, immigrants are, in effect, encouraged to enter the country illegally.Skeptics often say that all business wants is a steady supply of low-wage workers. Bringing the estimated 11 million undocumented immigrants into the legal workforce means that current workers no longer will have to compete with undocumented workers willing to accept below-market wages. Ultimately, wages will go up.Those who came or stayed here in violation of the law must face consequences -- admitting their wrongdoing, paying a fine and undergoing a criminal background check.Those who qualify would have the chance to work, learn English and earn their citizenship.With support from both political parties and the president, realistic solutions for our immigration system are within sight -- solutions that will improve U.S. competitiveness, add jobs and drive growth. The stronger economy that results will benefit all Americans.Greg Brown heads Business Roundtable's Select Committee on Immigration.