A couple of comments:

> People with little economics training intuitively grasp this point. They understand that some human workers may lose out in the race against the machine. Ironically, the best-educated economists are often the most resistant to this idea, as the standard models of economic growth implicitly assume that economic growth benefits all residents of a country.

No important model of economic growth assumes that growth or technological progress benefits everyone. What is broadly assumed (and there's a lot of empirical evidence behind it) is that innovation is the prime driver of economic growth, particularly in advanced capitalist economies.

Economic growth means that society is gaining wealth in aggregate. And so long as the pie is growing, it is always possible, in principle, to allocate the gains in a Pareto-efficient manner (that is, in a manner in which everybody gains) through the political process. Therefore many economists consider the "distributional" question, concern about who gets what, to be of secondary importance to their field. They see their job as figuring out how to maximize the size of the pie and leave it to others to figure out how to divvy it up. (Economists do of course have a lot to say about how various ways of distributing the gains from growth affect the prospects for future growth.)

> Shortly after the Luddites began smashing the machinery that they thought threatened their jobs, the economist David Ricardo, who initially thought that advances in technology would benefit all, developed an abstract model that showed the possibility of technological unemployment.

What the author is eliding here is Ricardo's development of the idea of comparative advantage [0], one of the truly remarkable ideas in economics. Comparative advantage is basically the idea that even if one country (or firm, or group of people, or single person, or whatever economic unit you want to think about) is better at producing every conceivable good or service, that country (firm/group/person/etc) will still gain from specializing in producing the good or service it (they/he/she/etc) is relatively best at producing, then trading with others—who will also gain by the interaction.

This insight does not mean that everyone will always gain from freer trade, or from innovation (which can be thought of as essentially similar in this regard to a relaxation of trade barriers with a country that's particularly adept at producing one good or another). But it does suggest that there is a net gain to be had from these developments. And, again, economists are primarily concerned with growing the pie.

> At least since the followers of Ned Ludd smashed mechanized looms in 1811, workers have worried about automation destroying jobs. Economists have reassured them that new jobs would be created even as old ones were eliminated. For over 200 years, the economists were right.

And that, really, is where I would leave things. There is very little to suggest that technological progress is about to take on a fundamentally different character, or entail much different results, than it has had, and has done, throughout the course of human history. When the singularity arrives, let's have this conversation again.

0. http://en.wikipedia.org/wiki/Comparative_advantage