It’s been a memorable summer at the box office, and not in a good way.

Pictured: Bomb

The list of 2013 movie flops is a sad roll call of would-be blockbusters.  In the last month alone, five films that cost more than $100 million to produce have opened at a figure equal to less than one-fourth of their budget.  This unenviable quintet includes R.I.P.D. (opened at $12.6 million), Turbo ($21.3 million), White House Down ($24.8 million), and The Lone Ranger ($29.2 million with a whopping $225 million budget).

Superhero movies—or, more properly, Iron Man 3 and Man of Steel—continue to do well, as do animated features like Despicable Me 2 and Monsters University.  These films, coupled with a group of mild surprises like The Heat and the over-performing World War Z, have led some to contend that maybe things aren’t quite as bad as they seem.  After all, this summer’s overall domestic gross is still slightly higher than last year’s (although foreign markets are down by a sizable 13 percent).  Not only that, but, with The Wolverine, Smurfs 2, and Occupy-porn Elysium predicted to do well, the hand-wringing over the weak returns may be premature.

It’s a common refrain from the both the industry and industry experts whenever stories about sub-par movie performance crop up: “Look at the big picture,” they say.  “The grosses are fine.  Movies are as popular as ever.”

Except that this party line reflects a unique aspect (perhaps “charade”) of the movie business: An aspect that obscures the fact that the industry has been declining for years.

Film is the only entertainment medium whose primary measure of success is gross dollars.  Music measures number of albums or singles sold or downloaded.  Publishing measures number of copies sold or downloaded.  The same holds true for video games.  Television measures the number of people or households watching a given program.  Pay-per-view measures number of buys.

Movies are different.  Decades ago, some visionary decided that we would assess the success of a film by its gross revenue, notwithstanding the fact that inflation, varying ticket prices, and ever-increasing budgets through the years changed the significance of a film grossing a particular number of dollars.

The harsh reality is that improvements in electronics have closed the gap considerably between the home experience and the experience of going to a theater.  The audio / visual quality available at home now rivals that of a cineplex—and without the much-derided $10 bucket of popcorn.  People in 2013, particularly younger people, have come to expect the immediacy of iTunes or Netflix and the convenience attached to home viewing.

You can see the unmistakable “staying home” trend in box office performance over the last decade-plus.

But you have to know where to look.

Examining the all-time domestic gross chart on Box Office Mojo seems to suggest that all is well.  Of the Top 50 films of all-time, 40 of them have been released during the 21st century.  Sounds great, right?

Adjusting for inflation reveals a much different picture.

On that list, a mere six films from the current century crack the Top 50.  Worse, only one recent film—2009’s Avatar—ranks among the Top 25.  The Top 10 films were released in 1938, 1977, 1965, 1982, 1997, 1956, 1975, 1965, 1973, and 1937, respectively.

In 2013 dollars, the Ten Commandments grossed over $1,000,000,000 domestically, topping “Avatar” by better than 200 million.

Perpetuating the semi-fiction of sustained success allows for the industry to float headlines about new releases “breaking records” for a given weekend or genre of film, even when no movie this century has even come close to making as much money in adjusted terms as, say, The Sound of Music or The Ten Commandments.  Even Avatar couldn’t manage to earn half as much as Gone with the Wind in adjusted dollars.

This is even more troubling when considering that there are far more theaters and far more Americans than there were decades ago.

Hollywood is able to hide its slow decline with some financial slight-of-hand, but, as the era of 4K televisions, 3-D at home, and first-run streaming content fast approaches, I can’t help but wonder if the industry as we know it is about to change dramatically.  Even insiders are saying that the days of opulent production budgets are probably numbered, at least when a film isn’t part of a proven franchise (read: A superhero sequel or an AAA animated title).

The failures of this summer provide some new cracks in the facade.  The sad fact is that, in a country with twice as many people and twice as many screens as we had about 50 years ago, and with more movies being produced, fewer tickets are being sold than were being sold at the beginning of this century.

The changing relationship that the public—especially Millennials—have with the movies may convert the theater experience into a niche activity, reserved only for “event” pictures and specialty business.  Eventually, the declining health of the industry may be impossible to hide.

For now, enjoy the rest of your summer blockbusters.