Sooner or later they were bound to solve this whodunit. The Reagan people were determined to burrow down and root out the cause of all these expensive social problems.

Finally, they have come up with their favorite candidate for the ultimate American Troublemaker title: Data. The Data did it, and now Reagan is doing it to the Data.

The latest agency in Washington to be "riffed" by the grim Reagan reaper is the primary data-gatherer, the Bureau of the Census.

In the case of the Census Bureau, RIF, "reduction in force," means a cutback in employees -- about 500 will be laid off and 5,400 given partial furloughs. But it also and inevitably means a cutback in information. This is what makes the riffing of the Census Bureau a case study of how Reagan is unraveling social programs.

The Bureau of the Census is the major outfit in Washington assigned to tell us something about ourselves. It's a collector, sorter and keeper of statistics. It tallies up our age, sex, race, income, employment and other geographic, social and economic facts.

Census is, in short, our public research bureau. And the Reagan administration is not feeling warmly toward the researchers, public or private, in the federal bureaucracy or academia. After all, they have long been in the business of gathering up the mischievous numbers.

During the era of creating federal programs, researchers were busy uncovering problems. The safety net was woven in large part out of their data.

The 1950s way of expanding government programs went somewhat further, but the process was similar. First, a group of people in academia or politics or the media would "discover" a social issue -- hunger for example. Then the researchers would go out and collect the numbers.

Once the figures were in, we knew how many people were hungry and where they were hungry. We had a certifiable problem. We held hearings, we called for solutions, we passed legislation and started distributing things like food stamps.

Now we have an administration that wants to turn this process around, to contract federal programs, or scatter them to the 50 state winds. You can't unravel it without unraveling the research. So it isn't a coincidence that the money to identify social problems has shrunk along with the money to study them and the money to alleviate them.

Meanwhile, if one agency is cutting food, shelter and medical care, the last thing the administration wants is to see another agency tallying up the pain. If one agency is cutting programs, they don't want another spewing out numbers that prove the programs are necessary. They are better off letting sleeping statistics lie.

The end result is that funding social research in this administration is as popular as leaking defense secrets. What we don't know can't hurt them.

The Bureau of the Census isn't going to fold up shop. Its basic functions are protected by the Constitution. But the bureau and the other agencies may be severely limited in gathering and sharing information. As for the academics who depend on federal grants, their studies of society have been crippled. But the rampant riffing of researchers adds an elegant simplicity to the whole Reagan plan. You may not be able to cure unemployment, but by golly, you can stop counting it. You may not be willing to help the poor, but you can stop offering up the proof of their proverty. You may not be willing to help the displaced homemaker, the abused child, the undernourished, but you can make them invisible again.

Who knows, without all that data around to keep bothering us, poverty, unemployment, even hunger, will just disappear. This is the way they solve problems in the New Reagan Era: they kill the Data.