Tokyo, Feb. 5 (Bloomberg) -- Japan's index of leading economic indicatorsrose to the 50 percent boom-or-bust mark in December, suggesting theeconomy isn't headed for recession. The leading index, which gauges economic activity in about six months,rose to 50 percent in December, up from 30 percent in November, theCabinet Office said in a preliminary report. A reading of 50 percent means half the available components that makeup the index improved compared to three months earlier, and suggests theeconomy will expand. ``The business cycle is turning down but is not collapsing,'' said YoshitoSakakibara, senior economist at Merrill Lynch (Japan) Inc.. Increases were registered in four of the eight available components - newcar registration, floor space of housing starts, money supply and joboffers. Meanwhile, the index of coincident economic indicators also bouncedback above 50 percent in December after falling short in November. Theindex, which measures current conditions, posted a reading of 71.4percent in December, up from 30.0 percent in November, the reportshowed. The indexes are calculated by dividing the number of positive componentsby the total, and gauges the direction the economy is headed. A readingabove 50 percent points to expansion, though isn't a measure of howmuch growth is in store. The level economic activity can be seen through the composite indexes.The leading composite index rose 0.2 percent to 102.6 in December, whilethe coincident index rose 0.7 percent to 108.3, the report said.