Are high waists correlated to the Economy?

My first assignment back at uni, (studying for my Masters in International Fashion Management) is to look at trends for SS14.

Trends go further back than just the catwalk. Economists have noticed that the fashion industry has fluctuated along with the stock market, hemlines rising when the economy is thriving, and dropping when it slows or crashes. Known as the hemline index (launched in 1929 by economists George Taylor).

I began to research this, then I got side tracked and began to wonder whether this relates to lingerie, whether there is any truth to high waists mirroring the economy or because I was looking for the trend, I did begin to see more high waisted lingerie and swimwear in the 1930s/50s/70s/90s/2010s.