At 12:01 a.m. this morning, I watched the final film in the wildly successful Harry Potter series.

It’s been the second-highest grossing film franchise of all time, behind the 22 movies in the James Bond franchise (Harry Potter has managed to do it with eight).

The ticket for this cinematic extravaganza “only” set me back $13.50.

Back in 2001, when the first movie came out, a ticket cost me $5.50. Do the math, and you’ll find that’s an increase of 145 percent in 10 years.

Now I’m willing to grant that the price increase can be justified from a few factors. The actors have grown into their roles and gotten better. The special effects have vastly improved.

But if anything, technical improvements tend to be deflationary.

Consider this somewhat extreme example: The price of a megabyte of computer memory has fallen from $700 in 1981 to $0.08 today. As technology gets better and production methods become more efficient, prices go down.

So, I’ve got to believe that the majority of the price increase comes from one thing: The wizardry of inflation.

Why? For starters, money supply has doubled since 2001.

That might not sound so bad, but consider this: What if the money in your bank account doubled overnight? Chances are you’d be tempted to spend more. Maybe not all of it, but you’d certainly buy some finer clothes, have a nice dinner out.

If everybody’s money doubled overnight, rising prices would be clear. From one day to the next, the amount of goods in our economy can’t grow by much at all. But the money supply sure can.

So doubling everybody’s money overnight doesn’t make everyone twice as wealthy. It just means that everything would roughly double in price.

Of course, inflation doesn’t happen that fast for a reason. At the moment, a little inflation is perceived as a good thing: Workers get regular raises, there’s the general appearance of prosperity, and prices tend to rise slowly and unevenly. It gives central bankers the appearance of benevolent wizards.

When inflation rises much higher, the sham of simply creating more money is seen for what it truly is: A cheap trick that’s gone horribly wrong.

That’s why inflation is a slow, steady, and insidious process. And much like a certain villain in a series of fantasy movies, Federal Reserve Chairman Ben Bernanke has already taken the wizardry of monetary policy to dangerous levels.

Under Bernanke’s tenure, interest rates have been near zero since late 2008. The Fed has turned to buying Treasurys with two rounds of quantitative easing. This program allowed the money supply to expand when consumers don’t want to take advantage of low interest rates and borrow.

What’s next? Probably more of the same. This week, Bernanke stated before Congress that he was “prepared to respond if stimulus was needed” with a third round of easing, following the failure of the first two rounds to get the economy out of the doldrums.

In other words, when the current illusion of prosperity wears off, cast the same spell again and hope it sticks.