A monthly measure of optimism among small business owners continues to retreat even as concerns mount over labor shortages and inflation.

The National Federation of Independent Businesses reported its Small Business Confidence Index edged down a tenth of a point to 90.6 in November. The index has remained below its 50-year average of 98 for 23 straight months.

“Even with the growing economy, small business owners have not seem a strong wave of workers to fill their open positions. Inflation also continues to be an issue among small businesses,” 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 November, five of 10 components of the index advanced, four declined and one remained unchanged.

The proportion of NFIB members who responded to the survey upon which the November index was based who expected the economy to improve rose a point from October. But at a net negative 42 percent, more members anticipated worsening conditions.

A net 23 percent of members planned capital outlays in the next few months, down a point. A net 8 percent said they considered now a good time to expand, up two points.

The share of owners who expected increased sales rose two points. But at a net negative 8 percent, more forecast lower sales.

Expectations for increased earnings remained unchanged at a negative 32 percent. Among those members reporting lower profits, 36 percent blamed weaker sales, 16 percent increased materials costs and 14 percent higher labor costs.

A net 18 percent of members reported plans to increase staffing in the next three months, up a point. A net 40 percent reported hard-to-fill positions, down three points. A net 30 percent is expected to increase compensation in the next three months, up six points from October to the highest level in two years.

The proportion of members who said they plan to increase inventories fell three points to a net negative 3 percent. The share of those who deemed current inventories too low rose three points to a net 0 percent.

Asked to identify their single most important problem, 24 percent cited quality of labor, followed closely by inflation at 22 percent.

A net 25 percent of members reported raising average sales prices, down five points from October.