Overall, clothes have been getting cheaper for decades, ever since apparel manufacturing started moving to developing countries, where production costs are significantly lower. In the U.S., the world’s largest apparel market, 97.5 percent of clothing purchased is now imported, according to the American Apparel & Footwear Association. That percentage has risen steadily for years. As recently as 1991, it was just 43.8 percent.

The spread of fast-fashion chains has helped spur the process. Zara, which pioneered the fast-fashion model, opened its first U.S. store in 1989, the same year that the U.S. chain Forever 21 opened its first location in a mall.

Data from the U.S. Bureau of Labor Statistics’ Consumer Price Index, which measures the change in U.S. retail prices, shows that while retail prices of goods overall have gone up, clothing prices have generally decreased.

Apparel Has Gotten Cheaper Though Overall Prices Have Increased

Data: Bureau of Labor Statistics

This means Americans are able to buy more clothing, and as incomes have increased overall, they spend less of their money on it.

Indeed, clothing accounted for 14 percent of Americans’ total discretionary expenditures in 1901, had decreased to 10.4 percent by 1960, and then plummeted to just 3.1 percent in 2013, according to the Bureau of Labor Statistics.

Spending on Clothes as a Share of Total Spending

Data: Bureau of Labor Statistics

These conditions make it easy for people to buy things they don’t need or even really want. One email survey of American women found that those who responded owned an average of $550 of unworn clothes; and the Council for Textile Recycling estimates that Americans throw away 70 pounds of clothes and other textiles each year.

In 1991, Americans purchased an average of 40 garments per person, according to the American Apparel & Footwear Association. In 2013, it was up to 63.7 garments, down from a peak of 69 just before the recession. That means that, on average, Americans buy more than one item of clothing each week.

The consumption isn’t by any means limited to the U.S. Women in Britain, for instance, now own four times as much clothing as they did in 1980. This glut of clothing is having effects beyond stuffing our closets. About 10.5 million tons of clothes end up in American landfills each year, and secondhand stores receive so much excess clothing that they only resell about 20 percent of it. The remainder is sent to textile recyclers, where it’s either turned into rags or fibers, or, if the quality is high enough, it’s exported and cycled through a cutthroat global used-clothing business.

Determining exactly how much time people spend shopping for clothing isn’t simple. The U.S. Bureau of Labor Statistics conducts an American time use survey, but clothes shopping is lumped in with shopping for everything else except groceries and gas. It is clear, however, that more and more Americans are shopping online, and early evidence suggests that they are shopping more often. Andrew Lipsman, vice president of marketing and insights at the Internet research firm ComScore, says that mobile shopping in particular has “exploded.”