Here is an interesting book excerpt talking about how the 1929 Depression came about. After 80 years of experience, we may need to learn the same lessons again. These words were written in 1937, after the Depression had taught a few lessons. Excerpt follows:

“Courtesy” and “Service” are the watch-words of merchandising today [1937]… because, in the final analysis, both the employer and his employee are EMPLOYED BY THE PUBLIC THEY SERVE. If they fail to serve well, they pay by the loss of their privilege of serving.

During the depression, I spent several months in the anthracite coal region of Pennsylvania, studying conditions which all but destroyed the coal industry. Among several very significant discoveries, was the fact that greed on the part of operators and their employees was the chief cause of the loss of business for the operators, and loss of jobs for the miners.

Through the pressure of a group of overzealous labor leaders, representing the employees, and the greed for profits on the part of the operators, the anthracite business suddenly dwindled. The coal operators and their employees drove sharp bargains with one another, adding the cost of the “bargaining” to the price of the coal, until, finally, they discovered they had BUILT UP A WONDERFUL BUSINESS FOR THE MANUFACTURERS OF OIL BURNING OUTFITS AND THE PRODUCERS OF CRUDE OIL.

[And now, in 2009, the greed of the oil companies has paved the way for “green” businesses to take over. -CM]

“The wages of sin is death!” Many have read this in the Bible, but few have discovered its meaning. Now, and for several years, the entire world has been listening BY FORCE, to a sermon which might well be called “WHATSOEVER A MAN SOWETH, THAT SHALL HE ALSO REAP.”
Nothing as widespread and effective as the depression could possibly be “just a coincidence.” Behind the depression was a CAUSE. Nothing ever happens without a CAUSE. In the main, the cause of the depression is traceable directly to the worldwide habit of trying to REAP without SOWING.

This should not be mistaken to mean that the depression represents a crop which the world is being FORCED to reap without having SOWN. The trouble is that the world sowed the wrong sort of seed. Any farmer knows he cannot sow the seed of thistles, and reap a harvest of grain. Beginning at the outbreak of the [first] world war, the people of the world began to sow the seed of service inadequate in both quality and quantity. Nearly everyone was engaged in the pastime of trying to GET WITHOUT GIVING.

These illustrations are brought to the attention of those who have personal services to market, to show that we are where we are, and what we are, because of our own conduct! If there is a principle of cause and effect, which controls business, finance, and transportation, this same principle controls individuals and determines their economic status.

Napolean Hill: THINK AND GROW RICH (1937)