Ever since the invention of the wheel in Mesopotamia around 3500 B.C., technological innovation has been improving our lives. Because new devices and processes help us produce more (output) with less (labor input), prices fall, real wages rise and we are all better off.

If there is a free lunch in this world, it's productivity growth.

There is even an economic school of thought, known as real business cycle theory, that views technology shocks as the main driver of the business cycle: not the central bank, not fiscal policy, not animal spirits or expectations.

Technology, in fact, is always equated with good: More is better.

I'm all for progress, but I keep wondering if some of our latest innovations are productivity-enhancing or just a pure waste of time.

Every time I'm in Manhattan, I marvel at the number of people crossing the street or sitting down to lunch with a friend without taking their eyes and fingers off their electronic devices. I can even predict the effect such interconnectivity will have on the individual psyche.

Twenty years from now, researchers will publish studies about how the teenagers of today, addicted as they are to texting abbreviated word forms, have trouble relating to one another. Educators will bemoan the inability of the youth of America to write.

I didn't have to wait 20 years. Sherry Turkle, a professor at Massachusetts Institute of Technology, described this phenomenon perfectly in an April 21 New York Times article titled, "The Flight from Conversation." She called it "alone together."

"We live in a technological universe in which we are always communicating," Turkle, a psychologist, wrote. "And yet we have sacrificed conversation for mere connection."

Social networking is just such an alone-together pursuit. Last year, Bloomberg journalists were encouraged to set up Twitter accounts. I reluctantly complied. I don't have a Facebook page, was never tempted to create one and didn't understand the value of letting friends know that I was eating a peach or walking the dog.

At first I restricted my tweets to my column and blog posts. I never looked at Twitter in between. Then I started interacting with people, and it became contagious, more like a game. Who was retweeting my posts? How many followers did each tweet produce? What was my tweet-to-follower ratio?

My most attention-grabbing tweet was something snarky I wrote on Nov. 14 during L'Affaire Petraeus: "Both Petraeus & Broadwell were married. Yet now she's his 'mistress.' Do we have an equivalent word in English for him?"

I got dozens of suggestions and 50 new followers. But what was the value? It seemed like a huge distraction from my work. If we as a nation are twittering our lives away, surely it must be manifesting itself in the statistics.

I decided to go to the source on labor productivity: the Bureau of Labor Statistics. I asked one of the economists there if he could help me determine how my personal productivity was being affected by tweeting. Once I became an expert, I was sure I could extrapolate the results to the universe at large.

You probably guessed: It's not that easy. In its monthly calculation of output per hour worked, or productivity, the BLS uses revenue as a proxy for output. Total hours worked is used as a proxy for labor input. Productivity is computed from the two numbers.

What about the effect on the quality of my work? If I'm spending more time tweeting and less researching and writing my column, surely the quality suffers.

Goods can be adjusted for quality changes. It's harder with services and is almost impossible for my output. (Readers, however, have no problem providing instantaneous qualitative assessment: It stinks.) The good news is, until my slacking off starts to affect Bloomberg LP's sales, my personal productivity isn't captured in the statistics. The bad news is, I may lose my job.

The difficulty of capturing the Twitter effect in the aggregate data notwithstanding, the productivity-sapping side of social networking doesn't stop there. A recent study by Keith Wilcox, an assistant professor at Columbia Business School, found that Facebook was making people fat. Yes, fat. It seems that social networking improves self-esteem and, in so doing, reduces control over our choice of snacks.

The study said nothing about the effect on productivity. That's a leap I'm taking. To the extent that obesity and its secondary effects require treatment, it means less time devoted to work.

Does that make sense? I think I will share the idea with my Twitter followers and see what they think. Then I'll get back to work.