Business executives are less optimistic about the U.S. economy in the third quarter than in the second, according to the American Institute of CPAs’ third-quarter economic outlook survey. It found 44 percent of business executives are optimistic about the U.S. economy, down from 49 percent in the second quarter. However, the second-quarter reading was the highest since early 2007.

In the third quarter survey, 15 percent of respondents said they have too few employees and are planning to hire in the next 12 months, up from 12 percent in the second quarter and 9 percent a year ago. Another 19 percent say they have too few employees but are reluctant to bring on new staff. Fifty-three percent of companies reported they have the right number of employees, and 11 percent said they have too many employees.

Executives who said they were optimistic about their company’s prospects slipped to 55 percent in the third quarter from 57 percent in the second quarter, and the number of companies who expect their businesses to expand held constant at 62 percent.

Those who continue to be optimistic cite improvements in housing and construction and consumer spending as the most significant factors influencing their decision, followed by the employment situation. Those with a neutral or pessimistic view cited the challenges of the Affordable Care Act and political leadership as the most significant factors.

The survey polled CEOs, CFOs, controllers and other certified public accountants in U.S. companies who hold leadership positions.

The CPA outlook index — a comprehensive gauge of executive sentiment within the survey — remained unchanged from last quarter at 69 points, matching a post-recession high last reached in the first quarter of 2012. However, each component of the index is higher now than a year ago, with U.S. economic optimism up 21 points year-over-year, despite this quarter’s dip. The employment component of the index rose to 64 points in the third quarter, up from 62 points in the prior quarter and 59 points in the third quarter of last year.

“We’ve seen expectations on hiring and business expansion gain steadily throughout the year,” said Arleen Thomas, AICPA’s senior vice president of management accounting and global markets. “Our latest survey results support that but also show some renewed concern about prospects for the U.S. economy.”

The survey of AICPA business and industry members was conducted between Aug. 13 and Aug. 29, 2013, and had 1,228 qualified respondents.