A measure of optimism among small business owners has rebounded on more upbeat expectations, but concerns persist over inflation and labor shortages.

The National Federation of Independent Business reported its Small Business Optimism Index rose 1.9 points in August. But at 91.8, the latest reading remained below the 48-year average of 98 for an eighth straight month.

“Owners are managing the rising costs of utilities, fuel, labor, supplies, materials, rent and inventory to protect their earnings. The worker shortage is impacting small business productivity as owners raise compensation to attract better workers,” said Bill Dunkelberg, chief economist of the NFIB.

The NFIB bases the index on the results of monthly surveys of members of the small business advocacy group, most of them small business owners. For August, seven of 10 components of the index increased, two decreased and one remained unchanged.

The proportion of NFIB members who responded to the survey upon which the August index was based who expect the economy to improve over the next six months rose 10 points from July to the highest level since February. But at a net negative 42 percent, more of those who responded still anticipated worsening conditions.

A net 25 percent of respondents reported plans for capital outlays, up three points from a month ago. A net 5 percent said they consider now a good time to expand, up a point.

The share of those who expect increased sales also rose 10 points, but was at a net negative 19 percent.

Expectations for increased profits fell, however — seven points to a net negative 33 percent. Among those reporting lower profits, 36 percent blamed rising material costs and 23 percent cited weaker sales.

The proportion of respondents who said they plan to increase staffing rose a point to a net 21 percent. A net 49 percent reported unfilled job openings, unchanged from a month ago.

Asked to identify their most important problem, 29 percent cited inflation — down eight points from July and the largest proportion since the fourth quarter of 1979. Another 26 percent cited quality of labor.

A net 53 percent of those who responded reported raising average selling prices, down three points. Price hikes were most frequent in the construction, retail, transportation and manufacturing sectors. A net 46 percent reported raising compensation.