What economic statistics mean to you and your wallet

They mark the phases of the nation's economy like the ticking of some giant clock. Month after month, quarter after quarter, a wave of statistics pours out of government offices and private organizations. They give us a picture of the economy, tell us how it's doing, reflect past economic policy decisions, and form a basis for future decisions.

For individual Americans, all these numbers may seem like nothing more than something to keep statisticians busy, but they are worth watching:

* If you think your paycheck isn't paying for as much as it used to, the consumer price index tells you how right you are.

* If it seems you've been reading an unusual number of stories about factory layoffs, the unemployment figures confirm your observation.

* If you read that the Federal Reserve Board is easing monetary policy, money supply growth tells you if that's true or not.

* And if your particular money market fund doesn't seem to be beating inflation as handily as it did a few months ago, the funds' average yield figure tells you that you're not alone.

Some of these indicators, like gross national product and consumer prices, receive a great deal of public attention, but others that pass quietly through the media are just as important. And while some indicators - such as consumer prices and personal savings - are considered flawed, we watch them anyway because, until they are changed, they are the best we have. So, as long as they are used by so many people, a primer of some of the numbers in the accompanying chart may be useful.

Of the overall economic indicators, the three we hear of most often are gross national product (GNP), inflation rate as measured by the consumer price index (CPI), and the unemployment rate. Gross national product

The GNP is a figure that often tells us when we are in a recession. The shorthand definition of a recession is two or more consecutive quarters of GNP decline.

The GNP measures the output of a nation's goods and services. It is broken down into four categories: consumer spending; private investment, including business investment in buildings and equipment; the balance of imports and exports, or net exports; and purchases by federal, state, and local governments, including military salaries.

Figuring out what to include in GNP can be tricky, explains Larry Moran, an economist with the Bureau of Economic Analysis at the US Commerce Department. A pencil, for instance, may or may not be part of the gross national product.

''If you buy a pencil for your own use, that pencil is figured in the GNP,'' Mr. Moran says. ''But if The Christian Science Monitor buys a pencil for you to use at work, the pencil is not incuded in the GNP. Presumably, the cost of the pencil is figured in the cost of the Monitor, which is part of the GNP.''

Adding to the complexity, gross national product is reported two ways: as nominal GNP, the total for the quarter; and real GNP, which is GNP after removing the effects of inflation. Nominal GNP is measured in current dollars. Consumer price index

The common barometer of inflation is the consumer price index, which follows price changes for a ''market basket'' of goods and services. The basket includes food, housing, transportation, fuel, medical care, clothing, entertainment, and other goods and services. In 85 urban areas, the prices of some 385 items are tracked in nearly 25,000 grocery and department stores, hospitals, gas stations, and other outlets. Also, 36,000 renters and homeowners are surveyed to come up with the CPI's ''housing component.''

Many economists criticize the CPI's housing component. Changes in housing prices are checked every month. Because homes are so expensive compared with other products, it is argued, this factor weighs too heavily in the CPI. Few Americans buy a new house every month. The result, these economists argue, is an ''inflated'' index that helps push inflation even faster, because automatic cost of living adjustments in labor contracts, social security payments, and other outlays are tied to increases in the CPI. The Labor Department's Bureau of Labor Statistics plans to shift housing cost changes from new homes to a rental equivalent in 1983. Unemployment rate

Usually on the first Friday of every month, the Labor Department comes out with the unemployment rate. To get this figure, it conducts a household survey covering some 60,000 homes, asking the employment status of people 16 and older. If people did not work the week of the survey but tried to find a job, they are counted as unemployed. If they have given up looking for work, they are not counted. This growing group of ''discouraged workers'' has caused critics to call for changes in the way unemployment is calculated so that discouraged workers are included. ''Discomfort index''

The last two indicators, consumer prices and unemployment, were married by Jimmy Carter in 1976 when he was running for President. He added them and called it a ''misery index.'' Today it goes by a less harsh term: ''discomfort index.'' Merely add the monthly inflation and unemployment rates to determine the discomfort index for that month. For example, 8 percent unemployment and 10 percent inflation yields a discomfort index of 18. While this is not a bona fide economic index, some political analysts see it as a barometer of how the economy is affecting people, thereby having an impact on the election prospects of the administration in power. Implicit price deflator

A cousin of the CPI, this measure is also known as the ''GNP deflator.'' Many economists say this is a more accurate indicator of price changes than the CPI. Basically, the deflator measures prices changes for all components of the GNP. For example, the consumer spending component of the GNP is adjusted for price changes - or deflated - by dividing this category by the appropriate consumer price index. Business spending for raw materials, equipment, and semifinished goods is deflated by an index of wholesale prices. One thing the deflator does, Mr. Moran says, is take into account changes in consumer spending patterns that result from inflation. More people might buy cheaper, off-brand television sets, for instance, because prices for the major brands have jumped. Savings rate

Another guide to economic conditions is the savings rate. The Commerce Department subtracts the amount Americans spend from their after-tax disposable income. The difference is the savings rate. Because of this method, many people regard this rate more as an indicator of savings trends than as an accurate report on how much people are socking away. One reason this system can result in an inaccurate figure is the fact that many people do not report income to avoid taxes.

Still, the savings rate is closely watched, partly because Americans tend to have one of the lowest savings rates in the industrialized world. With a rate that hovers at around 5 percent, we save about a fourth of what the Japanese put away and a third as much as the West Germans. If the savings rate can be increased, Reagan administration officials who pushed for tax cuts argued, it would increase the investment pool, help lower interest rates, and in the long run help boost business productivity. Productivity

This is one of the measures that will tell those administration economists - and the rest of us - if they were right in regard to their goal of stimulating savings and investment. For the last reporting period, the third quarter of this year, productivity dropped 1 percent. This means it took 1 percent more hours to produce the same amount of goods and services as were produced in an hour during the second quarter. In that quarter, the rate of increase in productivity was 2. 8 percent, meaning the goods were produced in 2.8 percent less time than in the preceeding quarter. The lower rate in the third quarter does not mean workers loafed for three months, a Labor Department economist emphasizes. Lower productivity can result from idle factories and equipment, silenced by recession. Index of leading indicators

While the GNP can tell us what the economy did in the past, the index of leading indicators tells us what's coming - sometimes.''

The index has predicted eight of the last five recessions,'' jokes Mr. Moran of the Commerce Department. Although it has forecast the last five recessions and forecast when they were about to end, it has also foreseen three post-war recessions that didn't happen. In one case, a major part of the index - housing starts - was taking a dive while the rest of the economy was holding up enough to prevent an official recession, Moran explains.

Using 1967 as a base of 100, Commerce Department economists take some 300 sets of economic indicators numbers and weigh them to come up with the leading indicator. A 1 point increase does not mean an increase of 1 percent in GNP; it is just the size of the increase compared with previous changes. M1-B money supply

Every week, the Federal Reserve Board announces changes in the nation's basic money supply. The various categories of money supply figures have changed a number of times over the years, and the ''B'' was added to M-1 in 1979, when the Fed announced plans to keep a closer watch on the supply of money, letting interest rates go where they may. M1-B is the money in people's hands that is available for immediate spending. It includes currency plus all forms of checking accounts and check-like deposits.

Lately, as the recession has set in and the economy has not expanded, the growth of the money supply has been below the Fed's ''target range.'' If money supply growth is above that range, the Fed is criticized for fueling inflation. If it is below the target, the Fed is criticized for not providing enough monetary fuel to keep the economy expanding or to help push it out of a recesssion. Money market funds

The amount of money in the money market mutual funds now adds up to more than handily with 15, 16, and 17 percent interest rates. Lately, however, money fund yields - like all interest rates - have been down. These days, they're in the 11 -to-13 percent range.

But more important, says Money Fund Report publisher William F. Donoghue, is the fact that the funds have been lengthening the average maturities on their investments from about 30 days in October to 36 or 37 days a week ago. They are doing this, he notes, in an effort to pay higher yields as long as possible in a falling-rate environment. When the fund managers think rates are heading back up , maturities will get shorter again. Free world oil inventories

In the highly unlikely event that all supplies of new oil in the world were stopped - if all oil wells just stopped pumping - how long could the West continue to use oil before it ran out? A look at free world oil inventories tells you that Western nations like to have about 90 days supply.

Finding this figure means looking at historical patterns of consumption, trying to account for emergency oil-use policies, and dividing this into world reserves, including oil in storage, in refineries, and on ships.

Sometimes, as in the recent oil ''glut,'' there was a good deal more oil around. Lately, however, supplies have been dropping, but remain close to normal. ''Supplies are at a level where we don't need to worry too much,'' a Department of Energy official said. ''But we shouldn't get complacent.''