JACKSON HOLE, Wyo. (Reuters) - Federal Reserve Chair Jerome Powell has begun putting his stamp on the U.S. central bank as someone who will rely more on data-informed judgment and less on some of the models and theoretical values that have shaped the Fed’s course in recent years but that Powell has said can be false guides.

FILE PHOTO: A cyclist passes the Federal Reserve building in Washington, DC, U.S., August 22, 2018. REUTERS/Chris Wattie

In doing so he may be laying the groundwork for a longer-than-expected rate-increase cycle, as discussion intensifies among policymakers about what level of borrowing costs is appropriate in an economy that is nearly back to full health. In addition, the full stimulative effects of President Donald Trump’s tax cuts and increased government spending may not yet have presented themselves.

On the other hand, while the drag that many businesses fear could result from uncertain trade policy has not materialized, if it does it could force an earlier end to the Fed’s rate-hike cycle.

Such two-way concerns are unfamiliar territory for a Fed that under Powell’s immediate predecessors had to focus mostly on just one kind of risk: too-low inflation and sub-par growth. Now, with unemployment at 3.9 percent - below what most economists believe is sustainable -- and inflation near the Fed’s 2 percent goal, the economic terrain looks less fragile.

In a keynote speech at the Kansas City Fed’s annual symposium here on Friday and in recent congressional testimony, Powell has laid out an approach he sees suitable to that new terrain. It relies on using judgment to balance risks on both sides, and he cautioned against relying too much on roughly estimated variables like the so-called neutral rate of interest.

The neutral rate is a theoretical level that in a healthy economy would neither boost nor restrain investment and spending; it can move around over time.

Powell leaned heavily on the idea that policymakers would have to feel their way to their destination, citing incidents from Fed history in which reliance on technical estimation led the central bank astray, while reliance on intuition led to better outcomes.

“It’s an informed intuition,” said Atlanta Fed President Raphael Bostic, who like other regional Fed officials talks with dozens of firms regularly to get a sense of what might show up in economic data in one or two months’ time.

With a background in markets and law, that approach may play more to Powell’s strengths, while lessening the influence of technicians who have focused on issues like estimating neutral rates of interest and full employment.

Those estimates are based on historical data and may not capture changes to the economy that are in motion but have not yet been seen in the flow of data -- the sort of situation that led former Fed Chair Alan Greenspan to argue against rate increases in the late 1990s because he felt rising productivity was not fully seen in government statistics.

“We’re getting to a place now where it’s less clear whether we should be worried about weakness in the economy or too much strength,” Bostic said on the sidelines of the symposium, attended by all his fellow Fed policymakers as well as central bank chiefs and economists from around the world. “On some level I think it’s good for us all to be talking about the fact that policy is much more bidirectional in its possibilities.”

The recently released minutes from the Fed’s last meeting held an important clue as well, acknowledging that statements about policy in relation to an estimated neutral level “could convey a false sense of precision.” That could be even more of a dilemma at a time when fiscal stimulus and other developments might actually be shifting the neutral rate higher, as many policymakers are beginning to suspect.

If that is the case, it would set the stage for the Fed to push rates higher than currently expected while arguing that monetary policy was not yet restricting the economy, but was rather appropriate for its strengths.

The Fed’s most recent projections point to two more rate hikes this year and three in 2019, more than what markets currently anticipate. At the same time, the Fed is shrinking its $4 trillion portfolio of bonds, a process that is exerting upward pressure on some financial market and consumer interest rates and as yet has no clear end point.

The Fed currently describes interest rates as “accommodative,” a statement that requires an estimate of the neutral level. That language is expected to be jettisoned soon as rates continue rising, and does not necessarily need to be replaced.

Beyond saying he sees further gradual rate hikes as likely appropriate, Powell did not lay out a certain path for interest rates, cautioning that preconceived notions of where policy should end up may steer the Fed off course.

Along with the neutral rate of interest, the Fed is struggling with how to assess background variables such as the level of unemployment that could be reached without putting pressure on inflation. The general thinking is that it has dropped, but finding that point has been elusive.

“These are unobservables, and he’s good about emphasizing that,” said James Bullard, president of the St. Louis Fed. “As economists we often fall in love with our models, I certainly fall in love with my models. But at the same time I’m aware, and I have to remind myself all the time about all the shortcomings of models.”