Witch combination of factors contributed most to the start of the great depression of the 1930s?

It was after world LL when the economy crashed. many recognize it as the stock market in NY crashing, but it's actually affects places all around the world. Main reasons for this great depression are. 1. the increasing debt to fund the war. 2. the higher demands on crops and and product and putting many farmers out of business. 3. The unbelievable lowered price on everything.