WASHINGTON, D.C. — If the U.S. minimum wage increases, it would have little effect on small-business labor costs, according to a survey of small-business owners released by Discover Financial Services. Seventy percent of the 1,000 small-business owners surveyed said an increase in the minimum wage to $7.25 an hour would have little effect on labor costs. The survey includes companies with five or fewer employees.While a bump in the minimum wage wouldn't affect labor costs, 29 percent of the survey respondents thought it might affect the price of products and services they use. The U.S. minimum wage is currently $5.15 an hour.In the recent midterm elections, voters in six states passed ballot initiatives to raise their hourly minimum wage — every state in which such an initiative appeared. All the initiatives call for additional increases tied to the cost of living.When the increases become effective, 29 states will guarantee a minimum wage higher than the current Federal minimum. Nancy Pelosi (D-Calif.), who will be sworn in this week as U.S House Speaker, has called raising the minimum wage a top priority.