(Bloomberg) -- The Federal Reserve should more closelymonitor the economic struggles of the bottom 60 percent of the economy when making policy since “averagestatistics” are camouflaging what’s really occurring in the U.S.,billionaire Ray Dalio wrote in a report Monday.

Dalio noted wide disparities in factors including labor,retirement savings, health care, death ratesand education between the top 40 percent and bottom 60 percent ofthe country.

The founder of Bridgewater Associates said it would be a“serious mistake” for the Fed to just focus on a national averageas it could lead the policy makers to see a brighter economicpicture than the reality.

“Because the economic, social, and political consequences of aneconomic downturn would likely be severe, if I were running Fedpolicy, I would want to take this into consideration and keep aneye on the economy of the bottom 60%,” Dalio said in his DailyObservations report. “Similarly, having this perspective will bevery important for those who determine fiscal policies and forinvestors concerned with their wealth management.”

The difference in the financial conditions for the two groups --due in part to whether they can take advantage of the market rally-- is a major cause of slowing growth, he wrote.

The gap between the two economies will only intensify over thenext five to 10 years, as changes in demographics will challengethe government’s ability to meet pension and health-care demands,while changes in technology will continue to impact employment, hesaid.

The disparities he listed include these:

• The top 40% now has on average 10 times as much wealth as thosein the bottom 60, up from six times as much in 1980

• Just a third of the bottom 60% saves any of its income, comparedto about 70 percent of the top 40

• Premature deaths among those in the bottom 60% are up 20 percentsince 2000, and the odds of a premature death within that group aretwice as high as the top 40

With fewer children growing up to earn more than their parents, thebottom 60% are more likely to think they’re worse off than theprevious generation.

Total health-care spending, including insurance, by the bottom60% is about half of the top 40. Many are skipping care due to thehigh costs, with 12% of the bottom 60 going uninsured.

Fed officials have struggled to understand contradictoryeconomic data and what that should mean for monetary policy. TheFederal Open Market Committee hiked rates in March and June,primarily spurred by the expectation that robust job gains wouldeventually raise wages and inflation.

Surprisingly low inflation in recent months, however, has causedseveral policy makers to waiver in their resolve to move again inDecember.

Unemployment fell to 4.2% in September, its lowest level in morethan 16 years, while inflation has languished well below thecentral bank’s 2% target.

Fed Chair Janet Yellen has called this a “mystery,” but hassignaled her desire to continue raising rates gradually. Investorssee the probability of a December hike at about 80%, according topricing in federal funds futures contracts.

Dalio has said the Fed has given itself limited room to maneuverin the event of a downturn, and therefore must be careful not totrigger one as it moves towards tightening monetary policy.

He has also said that the longer-term picture for the U.S. isworrying because of the abundant debt and non-debt obligations,like health care and social security, that are coming due, creatinga squeeze.

“This squeeze will come gradually, not as a shock, and will hurtthose who are now most in distress the hardest,” he said in a postin May.

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.