“We have reached the end game of economic growth through credit expansion,” Hicks said in an annual letter posted on the New York-based insurer’s website. “Despite over five years of central bank money printing, the amount of non-financial debt in the U.S. as a percentage of GDP remains higher than it was before the financial crisis.”

The ratio of the debt to the gross domestic product was about 2.4 at the end of December, compared with 2.2 seven years earlier. The borrowing total was about $41 trillion at year-end, including debt from households, governments and non-financial businesses.

Hicks has long lamented the Fed’s low-interest rate policy, which limits returns on fixed-income securities. In 2013 he compared stimulus efforts to Theodoric of York, a Saturday Night Live character “whose solution to every health problem was more bloodletting” even when there was no evidence the approach was working. Alleghany’s portfolio is valued at more than $18 billion and is comprised mostly of bonds.

The Fed has kept interest rates near zero since December 2008 and last year ended a bond-buying program that helped push the central bank’s balance sheet to more than $4 trillion. A plurality of economists believes that the Fed will boost interests rates in June for the first time since 2006.

While Alleghany also invests in stocks, the insurer’s equity bets trailed benchmarks in 2014. The company’s return on stock holdings was 5.6 percent, compared with 13.7 percent for the Standard & Poor’s 500 Index.

Rarely Smooth

“Equities appear to offer attractive returns only in comparison to the sub-2 percent interest rates offered on U.S. government bonds,” Hicks said.

Hicks joins John Finnegan, the CEO of Chubb Corp., in citing risks for insurers. Finnegan wrote in his annual letter published Monday that the lack of growth in the global economy and a stronger dollar could limit policy sales and investment income.

“If mature economies can’t grow through debt expansion, and if aggregate demand remains soft due to weak income growth, then it is hard to see the prospect for a strong global economy,” Hicks said, citing the risk of China’s shift toward increased reliance on domestic consumption. “Such transitions are rarely quick or smooth.”

Hicks guided Alleghany through the financial crisis and presided over annual stock advances of at least 15 percent each of the past three years. The company slipped 0.2 percent to $484.23 at 2:16 p.m. in New York, and is up about 4.5 percent since Dec. 31.