And yet

And yet is acceptable when yet is used as an adverb. When yet is used as a conjunction, and yet is redundant. For example, and serves no purpose in this sentence:

The numbers do offer a sobering picture, and yet it’s far from all gloom and doom.

And yet is commonly used to start sentences. In some cases, the usage comes from unfounded bias against using yet to start a sentence.

And yet no one would bet against Jobs being on this list in 10 years’ time.

Here, there would be nothing wrong with,

Yet no one would bet against Jobs being on the list in 10 years’ time.

Elsewhere, and yet at the start of a sentence is rhetorical shorthand, often followed by a comma and usually meaning, “That may be so, but . . .”

Ms. Hill, a 50-year-old voice-over actress, said she had been feeling a spiritual drift away from Christmas for several years. And yet, each December she continued to go through the motions of sending out holiday cards, decorating the house, buying gifts.

There’s no technical justification for this use of and yet, but we can’t fault the writer for using a common conventional phrase in an informal piece.

On the other hand, when yet is used as an adverb, and yet works fine:

It is also expected that tax rises and spending cuts, both those already announced and yet to come, will weigh heavily on the economy.