Here’s another sign the economy is stronger: Several major hotel chains are significantly raising the number of loyalty reward points needed to book a free room.

It’s a simple matter of supply and demand, said Joe Brancatelli, who writes an online column on business travel. An improving economy has spurred more travel, prompting hotels to raise rates.

“Demand is up so they can charge more,” he said of hotels adjusting their reward points programs.

Most of the chains adopting point hikes are shifting hotels to a higher tier in their respective programs. Each tier designates the points needed to stay in that hotel. The higher the tier, the more points needed.

For example, Starwood Preferred Guests, the program for the Westin, Sheraton and W hotels, among others, raised the rate by at least 25 percent on nearly 250 hotels.

Wyndham Rewards, which includes Days Inn and Howard Johnson, is raising the points requirement by as much as 66 percent on about 1,600 hotels around the world. At an additional 2,900 or so hotels the rates are dropping, and they are staying the same at about 2,700 hotels.

Hilton HHonors, which covers Hampton Inn, DoubleTree, Embassy Suites and Waldorf Astoria, among others, is hiking the points requirement on many of its hotels 14 percent to 50 percent.

The Marriott Rewards program, which includes Fairfield, Courtyard, Ritz-Carlton and TownePlace Suites, will raise the points requirement by at least 33 percent for more than 1,300 of its hotels. The program also created a higher tier for its most expensive hotels.

Hotel dreams up a new amenity

If you have trouble sleeping at a hotel, the folks at the Benjamin Hotel in Manhattan think they have just what you need.

First of all, the 209-room hotel offers a pillow menu with 12 different options, including a hypoallergenic and water-filled pillow.

The hotel also offers “white noise” machines that play soothing sounds to get your mind at ease. The hotel’s spa can also send a masseuse to your room.

But the Benjamin took its sleep program one step further last week by introducing a “work-down call,” the opposite of a wake-up call. You can arrange to have a sleep concierge call at a designated time to remind you to get ready for bed.

The rates at the Benjamin range from about $350 to $1,400 a night for the VIP suite.