"Good times prevail. In spite of the incessant noise coming from our nation’s capital, financial markets appear to be unphased, as stocks ascend to new heights almost daily. The current U.S. economic expansion has reached eight years. It is the third longest on record and in 18 months will capture the all-time longevity title. Although the expansion is mature and some “yellow flags” are emerging, there is a reasonably good chance that the record will be broken. In this month’s letter, Bill Longbrake provides updates on GDP and its components, employment, inflation, productivity, and interest rates."