"Inequities among children remain deep and stubbornly persistent," the authors wrote.
And the more persistent the customer, the more effort these companies expend on rebuffing them.
But one innovation has proved more persistent: the falling price of clothes.
Since these institutions were persistent, the legacy of past misgovernment continued to hold down incomes.
The impact on growth is relatively persistent; the greatest effect is felt more than two years after the change.
"Resilient, able to bounce back from setbacks, persistent — the fact that she ended up finishing her dissertation.
Noise is a stressor, and when it is persistent, the body's protective mechanisms do indeed become burdened, making the victims of noise vulnerable to mental and physical breakdown.
For mild to moderate depression, unless it is persistent, the National Institute for Health and Care Excellence (Nice) does not recommend medication as a first resort.
"There is controversy over how much cell renewal there is in the hippocampus and how persistent the stem cells are throughout life.
"If I hadn't been so persistent," the patient told me recently, "I don't know how long it would have taken me to get a definitive diagnosis.
To get a sense of how persistent the problem is, check out just the latest example of corporate tax dodges described this morning by my colleague Simon Bowers.
