As of January 20, the major U.S. stock market indices were down between just over 9 percent (DOW Jones Industrial Average, S&P 500) and nearly 11 percent (NASDAQ) since the beginning of the year, with large daily swings since the middle of last week.  Attached are some thoughts as to the reasons: decelerating economic growth in China, the falling price of oil, and Federal Reserve federal funds rate increases, all against the backdrop of slow-growing national economies around the world.