Skeptics point out that Texas benefits from a robust oil and gas sector. It's true that energy remains a key driver of the Texas economy and that other energy-producing states (Wyoming, North Dakota, etc) have been similarly propped up by these industries.
However, oil and gas prices are not sufficient to explain job creation in the state during Perry's tenure. They're capital-intensive industries, and so even when oil and gas is booming, the net employment effect is smaller than you would expect. The Dallas Fed has a good overview of the impact of energy prices on the Texas economy over the past 40 years. The most relevant bit for our purposes:
Although energy price shocks still aid the Texas economy in this period [1997-2010], the effects of a 10 percent oil price increase are smaller than in the first period [1970-1987]. The increase leads to gains of 0.5 percent in GDP, 0.36 percent in employment and 6.2 percent in the rig count.
A 10 percent natural gas price jump leads to gains of 0.3 percent in GDP and 4.9 percent in the rig count. The price increases do not affect employment significantly. In general, these results are consistent with the development of the Barnett Shale and the increase in natural gas production.
Or to put that in different terms, the oil and gas industry added 28,600 jobs between June 2010 and June 2011--nearly 13% of all the jobs created in Texas during that time, according to economist Karr Ingram. So, a lot of jobs, but it's not the whole story.
In general, I think Perry deserves partial credit for the job creation that has happened in Texas during his time in office. He also deserves some criticism for the things that that haven't gone well. I will elaborate more on this later.
In the meantime, since yesterday I've heard critics say that Perry is NOT responsible for having created jobs in Texas, but also that he IS responsible for the state's unemployment rate, which is currently at 8.2%, a point below the national average. On the face of it those claims strike me as slightly contradictory. I suppose the argument is that Perry has been lucky and now his luck's running out. That may be the case. I've argued in The Economist that Texas's budget shortfall and rising unemployment complicate Perry's claims to be a brilliant steward of the economy. There are also some economists who argue that Texas has a tendency to be slow to get into a recession, and slow to get out.
But the response the Perry people give is that no one can be fully immune from the effects of a global economic downturn. I think that's plausible, and even if the accomplishment turns out to be merely that Texas avoided a few years of a brutal recession, that’s not nothing. It means that the state, and more to the point the people in the state, were spared a lot of serious distress. During the worst of the national recession, when we were hearing horror stories from other places, people who were laid off in Texas were able to find new jobs relatively quickly. And I don’t just mean highly skilled people in Austin. Watching that happen made an impression on me.