NEW YORK — Video cassette recorders (VCRs) are now used in 70 percent of United States households with televisions, up 6.1 percent from last July, according to Nielson Media Research. Pay cable penetration stood at 29 percent of television households, down 1.4 percent. Of the cities with highest VCR penetration, nine of the top 10 were in the West, led by Anchorage, Alaska (83 percent). Boston ranked tenth with 75 percent. Among the top 10 areas for pay cable were several Southern cities led by Laredo, Texas (52 percent).