The main takeaway from the annual Kauffman Index of Entrepreneurial Activity released this week: When more people become employed, fewer people start small businesses.

According to the study, which is a leading indicator of new business creation in the United States, as America’s employment rate continued to improve in 2013, the country’s overall business creation rate fell for the second consecutive year.

The business creation rate was 0.28 percent in 2013, down from 0.30 percent of American adults per month who started businesses in 2012—or 476,000 new business owners per month in 2013 compared to 514,000 the previous year. And 2012 was down from 0.32 percent who started businesses in 2011.

However, the 2013 study also indicates that the number of new entrepreneurs not coming straight out of unemployment, also known as “opportunity” entrepreneurs, was much higher than at the end of the recession.

Dane Stangler, vice president of research and policy at the Kauffman Foundation, which conducted the study, said in a release: “The 2013 business creation rate signifies a return to levels that we haven’t seen since before the recession. While we have speculated in recent years that changes in entrepreneurship rates could be driven by labor market conditions, this new data provides the strongest evidence we’ve seen of this correlation.”

Other entrepreneurial activity noted in the study:

• The construction industry showed the greatest activity among industry groups in 2013, with an entrepreneurship rate of 1.27 percent, followed by the service industry at 0.37 percent.

• The entrepreneurship rate for all races and ethnicities declined from 2012 to 2013, as it did the year before.

• The only age group to raise its business creation rate was the 45-to-54 demographic, with 0.36 percent in 2013 compared to 0.34 percent in 2012. The lowest business creation rate among age groups was among those ages 20 to 34, falling to 0.18 percent in 2013 from 0.23 percent in 2012.

• The rate of business creation by veterans fell from 0.28 percent in 2012 to 0.23 percent in 2013, following an 18-year downward trend in the annual study. The decline can be attributed to fewer veterans of working age in the population.

• Although entrepreneurial activity rates were down in all regions, the state with the highest rate was Montana, where 610 per 100,000 adults created businesses each month in 2013, followed by Alaska (470 per 100,000 adults), South Dakota (410 per 100,000 adults), California (400 per 100,000) and Colorado (380 per 100,000).

Robert W. Fairlie, the study’s author and chair of the economics department at the University of California, Santa Cruz, said in a release: “Related to the findings for race and ethnicity, entrepreneurial activity among immigrants remains nearly twice as high as the native-born rate.”

The complete Kauffman Index of Entrepreneurial Activity with interactive data is available at www.kauffman.org/kiea.