As every school child knows, water is formed by the two elements of hydrogen and oxygen in a very simple formula we all know as H2O. Today we start a series that starts with the question, What are the elements that comprise deflation? Far from being simple, the "equation" for deflation is as complex as that of DNA. And sadly, while the genome project has helped us with great insights into how DNA works, economic analysis is still back in the 1950s when it comes to decoding deflation. Notwithstanding the paucity of understanding we can glean from the dismal science, in this week's letter we will start thinking about the most fundamentally important question of the day: is inflation, or deflation, in our future?

But quickly, I want to thank the many people who wrote very kind words about last week's letter. Many thought it was one of the better letters I have done in a long time. If you did not read it, you can read it here. And of course, you can go there and sign up to get this letter sent to you each week for free. Why not become of my 1 million (plus and growing) closest friends?

Among the economists and writers I regularly read, there are some who, if they agree with me, I go back and check my assumptions - I must have been wrong. Paul Krugman is one of those thinkers. I admit to his brilliance, but his left-leaning philosophy does not particularly square with mine, and I find that most of the time I disagree.

That being said, I strongly encourage you to read his essay in the New York Times Magazine, which comes out this weekend. It is worth the high price of the Times to read it, if you can't get it online. It is a very hard critique and analysis of the failure of current macro and financial economic thought, which didn't even come close to predicting the current financial malaise. Indeed, as he points out, most schools of thought said the state we are in could not happen. You can read at the essay if you are a member, or register for free if you are not. http://www.nytimes.com/2009/09/06/magazine/06Economic-t.html?_r=1.

Why does government data need to be revised so often? Is it conspiracy, as some claim, or is it methodology? And if it is methodology that leads to faulty data, then why not change the methodology? Is unemployment a lagging indicator, as conventional wisdom suggests? We look again at the underlying assumptions to suggest that things are not always the same. And finally, we look at unsustainable trends, fiscal deficits, and health care -- there is a connection.

But first, a quick note about the latest "Conversations with John Mauldin" that I just did with Don Coxe and Gary Shilling. These two esteemed analysts have different views on whether commodity prices will rise or fall, and are not afraid to make their views known. I edited the final transcript today, and I can tell you that even though I was "at the table" I learned a lot reading it the second time. If you want to understand the nature of what is a very central debate, this is a must-read. This was a VERY lively debate. Most of my friends know that I am not shy, but it was hard to get a word in edgewise as these guys went at it. It was great fun to watch.

And if you have not yet subscribed, you can go back and listen to my Conversation with Chris Whalen and Rick Lashley on the banking crisis, and see if you can figure out what motivated the Manhattan district attorney's office to call me asking for clarification. Plus the quintessential piece with Lacy Hunt and Ed Easterling on the fundamentals of the current economic crisis, which many subscribers said was worth the price of an annual subscription. And then there is the Conversation I did with Nouriel Roubini. It is all there for you.