A monthly measure of optimism among small business owners has edged up on more upbeat expectations for sales and earnings.

The National Federation of Independent Business reported at its Small Business Optimism Index rose a half point to 95.9 in August. Despite gains in each of the last two months, the index remains below the long-term average of 98.

“The index of small business optimism went nowhere in August. So the good news is it did not fall,” said Bill Dunkelberg, chief economist for the NFIB.

Given the latest index results, Dunkelberg said there’s little reason to expect dramatic second half-growth from the small business sector. “The small business sector will continue plodding forward — little risk of recession, but little risk of a boom as well.”

Small business owners responding to the survey upon which the August index was based didn’t seem too concerned about volatility in U.S. stock markets or the currency devaluation in China, Dunkelberg said. “Maybe it was too late in the month to be fully captured by the survey, so more might be revealed in September. But most small business owners have their capital primarily invested in their own firms, not other people’s firms.”

The NFIB bases the index on the results of surveys of members of the small business advocacy group. For August, five of 10 components of the index advanced, three components retreated and two held steady.

The proportion of small business owners responding to the survey who expect the economy to improve actually fell two points. At a net negative 6 percent, more owners anticipate worsening than improving conditions.

The share of owners planning capital outlays over the next three to six months remained unchanged at 24 percent. A net 10 percent of owners said they consider now a good time to expand, down two points.

A net 13 percent of owners reported plans to increase staffing, up a point. Meanwhile, 29 percent of owners reported hard-to-fill job openings, up four points to the highest reading for the year.

The proportion of owners planning to add to inventories rose a point to a net 1 percent. The share of owners who said their existing inventories are too low held steady at a net negative 6 percent.

The share of owners who expect higher sales rose a point to a net 7 percent. A net 10 percent of owners cited poor sales as their most pressing business problem, fourth behind taxes, government regulations and quality of labor.

The proportion of owners reporting higher earnings jumped four points. But at a net negative 15 percent, more owners reported profits were lower quarter to quarter than higher.