Forecasting Gauge in Jan. Unchanged : Economy: Current sluggishness believed likely to extend into midyear.

The government’s chief economic forecasting gauge was flat in January, the Commerce Department said today in a further indication that the economy’s current sluggishness will extend into midyear.

The lack of change in the index of leading economic indicators, designed to forecast economic activity six to nine months in advance, followed a revised 0.6% gain in December and a 0.1% advance in November. The index fell 0.4% in October.

Many economists had expected a slight increase in the January index.

Three of the 11 forward-looking statistics helped keep the index stable, led by a sharp increase in building permits during the warmest January on record.

Others showing strength were slower business delivery times and an increase in the backlog of manufacturers’ unfilled orders.

The biggest drag on the index in January was a decline in orders for consumer goods.

Other negatives were a drop in the money supply, a decline in plant and equipment orders, lower stock prices, a decrease in the price of raw materials, a drop in an index measuring consumer confidence and an increase in weekly unemployment claims.

One indicator, the length of the average workweek, was unchanged.

The various changes left the index at 145.3% of its 1982 base of 100. The index rose 0.8% from August through January after falling 0.7% the previous six months.

The December index originally was reported to have risen 0.8% but was revised downward to 0.6%, largely because of lower orders for consumer goods.

Despite the sluggishness, recent surveys indicate that business executives and economists generally believe the Federal Reserve is driving the economy down the right road, steering it away from a recession while braking the growth of inflation.

Seventy-two percent of the professional forecasters responding to a poll by the National Assn. of Business Economists said the central bank is on the right track.

And 56% of the business leaders participating in a survey by the National Assn. of Manufacturers said Fed policies are “just about right.”

But most of the business leaders and economists surveyed project continued sluggish growth in 1990 as the Fed keeps interest rates relatively high to slow the economy and keep prices under control.