Back in April, we wrote a column pointing out the difficult time economists and investors were having trying to forecast the direction of the economy and interest rates. The basic idea was that, previously, when the business cycle picked up a head of steam, inflation also began to increase. This concern for inflation in the past had always made the Federal Reserve leery of supplying too big a dose of monetary ease in fear of rekindling dreaded inflation. However, this time around, some of the ingredients that cause inflation -- rising labor costs and increasing commodity prices -- were missing.

Now it would seem that a lot more than that is missing. In fact, the economy seems to be straining just to keep its head above water. The average postwar recovery has lasted for 38 months, while the average 20th-century recovery has lasted for 25 months. The present recovery is now in its 44th month.

At this stage of the game, instead of a strong economy, we have an anemic one, handcuffed by weak energy and farming sectors.

The dollar has lost 30 percent of its value since February 1985, interest rates are down dramatically and we have a much easier monetary posture, but we are only showing 2.4 percent real growth for the first half of 1986 despite all of our efforts. The truth is that this is the first time since the early 1930s that we have attempted to cope with a deflationary situation, and the authorities as well as businessmen do not know what to do next. And this is a worldwide experience.

In spite of our predicament, it was surprising to see the bond Treasury market do so poorly following Federal Reserve Chairman Paul A. Volcker's testimony before the Senate Finance Committee and the news of the 0.5 percent rise in the consumer price index for June. The bond market was incorrectly disappointed with the chairman's remarks and is showing itself to be a volatile and impatient market. Perhaps old ideas concerning inflation and business cycles die slowly, but, sooner or later, these ideas have a way of coming back in fashion.Lebherz has 27 years' experience in fixed-income investments.