Is using commercially available yeast to create a sourdough starter effective? Numerous starter recipes talk about capturing wild yeast from the environment.

Many recipes, as well as questions and answers here, directly say or imply wild yeast is better and that deliberately added yeast is counter productive, but the explanations (if offered) seem to be vague handwaving more than fact. 

The most reasonable sounding argument against (to me as a lay-person) is that the yeast will not live long, but that seems specious to me. After all, that commercially available yeast was just grown somewhere a few weeks before it made it to the shelves.

It frankly makes little sense to me to gamble on the contents of the local environment at the point in time of trying to make a starter, when known safe and effective yeast exists that could be introduced.

(The question is not about safety or efficacy of wild yeast, not about substitution of yeast for a starter, and not about mixing yeast and starter at baking time; the point is to predictably, safely, and effectively make a starter.)
Don't do this. A sourdough starter contains several strains of yeast and bacteria in a fairly delicate balance. These consume sugars and produce CO2 and a range of byproducts. Commercial yeast is a different species of yeast, engineered to eat and reproduce much faster than any of the wild yeasts in your starter. Adding commercial  yeast to a starter will lead to the commercial yeast outperforming the wild yeasts and gradually replacing them. You will end up with a commercial yeast culture, rather than a sourdough culture.

Edit I realise I have somewhat misunderstood your question. The answer still holds, though: you cannot start with commercial yeast and expect to create a sourdough starter. The commercial yeast would prevent any wild yeasts and bacteria from colonising the starter. You can keep a culture of wild yeast (to some extent), but as @Chris H's comment states, it won't be sourdough.

If you want a better guarantee of success, your best bet is to somehow obtain an offshoot of someone else's starter. Some bakeries will be happy to give/sell you some, or you can try buying a starter online.