More affluent US viewers time-shift their viewing more

"Comparing the demographic household makeup of prime-time US TV viewers who watch live TV, who have a DVR but watch live TV, and watch time-shifted TV within seven days after live broadcast, it is clear that households which delay the viewing of TV shows with a DVR are more likely to be wealthy.
For example, 30% of households engaging in DVR playback have an annual income of $100,000 or more, compared to about 25% of DVR households watching a prime-time show live and only 15% of all households watching live TV. Conversely, 22% of all live TV households have an annual income of less than $25,000, compared to 10% of DVR households watching live TV and 7% of households watching time-shifted TV."

Source:  Data from Nielsen, reported by MarketingCharts, 29th December 2010

Note - lots more DVP/PVR data in the full article