There was plenty of positive data to back up the Federal Reserve's optimistic economic outlook in January: Housing, jobs and consumer spending looked good.

But a single question overshadowed almost all of that when members of the central bank's monetary policy committee met on Jan. 31 and Feb. 1: What will President Donald Trump's fiscal policies look like, and how will they affect the economy?

"While the minutes don't mention specific policies (or even the president and Congress) by name, the reference to 'more expansionary fiscal policy' is a nod to President Trump's hopes to give economic growth a substantial lift," Mark Hamrick,'s senior economic analyst, wrote in a note.

The committee's focus on the uncertainty associated with "yet-to-be implemented policies of the Trump administration and Congress remind us that officials want to see the specifics as well as their eventual impacts on the economy," Hamrick said.

While members announced after the meeting that short-term interest rates would remain at 0.5% to 0.75%, the range set in December after only the second hike since the 2008 financial crisis, Wednesday's recap of the meeting offered deeper insight into their thinking. 

Here's what you need to know:

1. FOMC members are cautious about adjusting monetary policy based on potential government spending. 

What they said: "Most participants continued to see heightened uncertainty regarding the size, composition, and timing of possible changes to fiscal and other government policies, and about their net effects on the economy and inflation over the medium term, and they thought some time would likely be required for the outlook to become clearer," according to the minutes.  

What it means: While Trump has said he supports cutting the top corporate tax rate from 35% to 15%, spending $1 trillion on infrastructure projects and trimming regulations, how much Congress will go along with -- and how quickly -- remains uncertain. Fed members need to know more to assess how the U.S. economy will respond and whether any action might be needed to avoid overheating.

2. Despite a stronger economy, there is considerable economic uncertainty that might impact interest rates moving forward.

What they said: There are a "number of risks" that could change members' current monetary policy stances, including "upside risks such as appreciably more expansionary fiscal policy or a more rapid buildup of inflationary pressures, as well as downside risks associated with a possible further appreciation of the dollar or financial vulnerabilities in some foreign economies, together with the proximity of the federal funds rate to the effective lower bound," according to the minutes. 

What it means: Since the Fed's meeting, data has shown that U.S. employers added 227,000 jobs in January, the most since June; existing home sales rose by 3.3%, the best level since February 2007; and the consumer price index moved up 0.6%, the most since February 2013, buoyed by climbing oil prices.

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While the economy has yet to hit the Fed's 2% inflation target, overly rapid employment and wage gains might lead to unsustainable growth that could precipitate a recession. Interest-rate increases, meanwhile, tend to strengthen the dollar, which can make U.S. exports costlier to buyers and hurt American manufacturers.

Should foreign currencies weaken at the same time -- as the British pound did after the United Kingdom voted last year to leave the European Union -- the effect would be compounded.

Those would all be elements in the Fed's interest-rates calculus, and many of them aren't yet clear. 

3. Fed members expect a rate hike "fairly soon." 

What they said: "Many participants expressed the view that it might be appropriate to raise the federal funds rate again fairly soon if incoming information on the labor market and inflation was in line with or stronger than their current expectations or if the risks of overshooting the Committee's maximum-employment and inflation objectives increased," the minutes read. 

What it means: The Fed signaled in December that it might raise interest rates as many as three times this year, to a range of 1.25% to 1.5%. Interest rate futures now indicate a 36% chance that one of those hikes will be in March, up from 31% at the beginning of the year. The odds of a May increase  climbed to 62% Wednesday, up nearly 3 percentage points in a single day.

4. There are going to be more discussions on the Fed's $4.5 trillion balance sheet.

What they said: Participants "generally agreed that the Committee should begin discussions at upcoming meetings about the economic conditions that could warrant changes in the existing policy of reinvesting proceeds from maturing Treasury securities and principal payments from agency debt and mortgage-backed securities," the minutes read.

What it means: As interest rates normalize and the economic expansion matures, the Fed expects to stop reinvesting the proceeds of maturing bonds and mortgage debt, a step that would begin to shrink the huge amount of liquidity the central bank forced into the economy by buying the securities after the 2008 financial crisis.

Its balance sheet roughly quadrupled in the process, and members don't think it's time to start shrinking that just yet.

The minutes point to little discussion of when the Fed may begin simply hanging on to the proceeds of maturing bonds, effectively reducing the money supply. 

Committee members said they expect to continue reinvesting until normalization of short-term interest rates is well under way.

"Markets appear to be banking on the Fed waiting to end its reinvestment program until the level of the fed funds rate is between 1% and 1.5%," said Ryan Sweet, director of real time economics at Moody's. "We believe the debate surrounding the balance sheet will heat up, but the balance sheet won't begin to decline until the first half of 2018."