The national activity index fell to minus 0.19 in February to indicate a rate of growth below the historical average. This index has been swinging back and forth across the zero line for the last year.

Production showed the sharpest monthly downturn, to minus 0.08 in February from plus 0.15 in January and reflecting substantial slowing in manufacturing output. Personal consumption and housing fell to minus 0.08 from plus 0.10 while employment fell to minus 0.02 from January's plus 0.10. The fourth component -- sales, orders, and inventories improved to minus 0.02 from minus 0.12.

The national activity index is expected to slow only slightly to 0.18 in February versus plus 0.23 in January which, thanks to that month's blow-out retail sales and employment reports, was the strongest in seven months.

The Chicago Fed National Activity Index (CFNAI) is a monthly index that tracks overall economic activity and inflationary pressures. The CFNAI is a weighted average of 85 existing monthly indicators of national economic activity. It is constructed to have an average value of zero and a standard deviation of one. Since economic activity tends toward trend growth over time, a positive index reading corresponds to growth above trend and a negative index reading corresponds to growth below trend.

This index is unique among regional Federal Reserve Bank indexes in that it is national in scope. Investors are eager to have insight into economic growth and inflation. This index combines 85 diverse and already released indicators from four broad categories -- production and income; employment, unemployment, and hours; personal consumption and housing; and sales, orders, and inventories -- into an overall index to measure economic performance. The index provides another measure with which investors can measure overall growth.