A big drop in construction job openings in January shows the tightrope Fed officials face as they try to calibrate plans for more rate hikes.

Driving the news: The number of construction job openings plunged by 240,000, or nearly 50%, to 248,000 in January compared to December, according to government data out Wednesday.

• It was the largest-ever monthly decline in construction job openings in the data series that stretches back roughly 20 years.
• Overall job openings, however, dipped only slightly in January, suggesting the overall economy remains strong.

Why it matters: The Fed has recently signaled that it's prepared to keep raising interest rates at a relatively rapid clip because inflation hasn't cooled as much as policymakers had hoped.

• Yes, but: There's a risk that rate hikes it already delivered — 4.5 percentage points over the last 12 months — haven't had their full economic impact yet.

Be smart: Economist Milton Friedman famously wrote that monetary policy works with "long and variable lags," which essentially means it can take years for Fed interest rate changes to work their way through the economy.

The bottom line: The sudden sharp drop in construction job openings in January — combined with the recent downturn in investment in residential construction and other measures of housing activity — suggests that the economy is still adjusting to the big rate hikes of last year, even as the Fed considers doing a lot more.

• That could set the stage for the Fed to accidentally over-hike, generating the hard economic landing many had been hoping to avoid.