Last year defied most expectations.

Synchronistic global growth led to a surge in corporate profits, which in turn pushed worldwide stocks higher. The FTSE All-World index shot up nearly 22 percent, its biggest rise since 2009.

U.S. markets were along for the ride: The Dow Jones Industrial Average increased by 25.1 percent, the S&P 500 index was up 19.4 percent and the NASDAQ Composite jumped 28.2 percent. The year’s progress propelled the second-longest bull market on record, which began in March 2009, toward a ninth anniversary.

But, we’re well into the first month of the new year, so it’s time to look ahead and to remind you that the stock market is not the economy and the economy is not the stock market. Despite the sterling performance of equities, only 54 percent of Americans report having money invested in the stock market at all (including individual stocks and stock market funds held inside or outside of retirement accounts).

Here are four questions to consider for 2018:

How will the economy perform? From the end of World War II until the Great Recession, gross domestic product averaged just over 3 percent growth annually. In the post-crisis years, growth has bounced around between 1.5 percent and 3 percent. Due to a slow start to the year, it looks like 2017 will show growth of about 2.3 percent overall. Most economists believe that the corporate tax cut will add a bump up in 2018, and estimates range from 2.5 to 3 percent GDP.

Will employment continue to improve? The economy has added about 175,000 jobs per month in 2017, down from previous years but stronger than expected this deep into the recovery. The unemployment rate, which is hovering at just over 4 percent, is down 0.5 percent from a year ago, and officials at the Fed are forecasting that it could go below 4 percent in 2018. With jobs continuing to grow and the unemployment rate at low levels, economists say that workers should see bigger increases in wages. Over the past few years, wages have increased by 2.5 percent to 3 percent annually; projections for the year to come are for increases of more than 3 percent.

What’s going to happen in the housing market? The real estate market was plagued by one big problem in 2017: There were very few homes for sale, which pushed up prices, probably by 6 percent for the year in 2017. On top of the inventory issue, there is a new worry on the horizon: The GOP tax plan will limit the deductibility of state and local taxes and property taxes to $10,000. Some analysts believe that the change could negatively affect high-cost, high-tax states such as New York, New Jersey and California.

Will interest rates continue to drift higher? The Fed raised short-term interest rates three times in 2017 and based on their predictions at the December meeting, they expect a repeat performance in 2018. But longer-term rates, as measured by the yield of the 10-year Treasury note, ended 2017 at 2.409 percent, down a touch from 2.446 percent a year ago. Relatively low interest rates have helped the economy overall as well as the housing and stock markets. But if growth accelerates, both the Fed and investors may push up rates more than currently anticipated, which would be good news for savers, bad news for borrowers and potentially bad news for investors.

Jill Schlesinger, CFP, is a CBS News Business Analyst. She welcomes comments and

questions at askjill@moneywatch.com.