A modest – but steady – compression in the spread between mortgage commitment rates on fixed- and adjustable-rate loans has gradually eroded the ARM share of new loan production, according to a new Inside Mortgage Finance ranking and analysis. But the fact that ARMs still account for a historically high 45.8 percent of mortgage originations during the first half of 2006 underscores the dramatic change that has taken place in the market since the... [Includes 2 data charts and 1 graph from the Inside Mortgage Finance database.]