Why would an owner of a quality horse be drawn to a big field allowance race when there will be other options. Owners realize the high cost of training a horse, and when they have one of better than average quality, they have to be striving for a 1,2,3 finish whenever possible.
What will happen is that the fields at Monmouth will draw one or two quality horses in big field races, or small field allowance races that are typically found in California.
Lurker is right. Bettors don't care how much owners make. What Monmouth is doing is putting lip stick on a pig. The best betting races will be the lower claiming races because they will attract quite a few droppers to run with the horses who belong in the class, so this will result in bigger fields, like the ones we saw when Fairgrounds had that meet where they gave away all the slot money they accumulated when the track was closed down.
Studies have shown that if you double purses, handle will rise 6%. Of course, this doesn't account for cutting dates, so I expect live handle to rise a bit more than the 12% (a triple purse increase) because fewer dates will lead to slightly increased attendance and players having a little more to bet on the live cards.
However, if racing is still off 10% over last year by the time Monmouth rolls around, we might see a 5% increase in handle tops over the year before (per date).