Just a caveat to my previous comment. There's one case in which subtracting inflation from GDP growth could be useful and, yes, would confirm Prof. Cole's assessment: if the reported GDP growth is NOMINAL GDP growth. But I'd be surprised if that's the case. Nominal GDP growth is a largely useless statistic that most economic agencies know not to puff up. Whenever it's reported, they immediately report the deflated GDP growth, because they understand that's the one we should care about. I know nothing about how Iranian economic agencies produce their statistics, or what are Prof. Cole's sources, but I would be very surprised if they simply reported the nominal GDP growth. If the 4% in the piece is nominal, then my previous comment is wrong. But it would be unusual if the stats agencies just reported that.
With all due respect to Prof. Cole, from whom I've learned a lot, the economic analysis of this piece is dead wrong. (I'm an economist, FWIW.) You don't simply subtract inflation from growth to determine real changes in purchasing power. If you want to get "real GDP growth" you subtract population growth from GDP growth. If you want to use inflation as a gauge of purchasing power you would have to use some other statistic, say, for instance, the change in the minimum wage (or average wage if that's available). But inflation by itself doesn't tell much about the change in the population's purchasing power. 4% of GDP growth and 9% inflation is not exactly an economic calamity. That inflation level is a bit too high, especially given the anti-inflation hysteria of many policy circles in the last years. But it's not in itself a huge issue. It is perfectly possible to have a well-functioning economy with those levels of inflation. The one caveat is to avoid it from spiraling, but 9% doesn't need to be the start of a spiral. Many economies have managed that. The 4% growth isn't bad either. It's mediocre, to be sure, especially considering Iran is a Third World country that should be growing more, but it's not bad either. And, to reiterate, subtracting the inflation rate from the growth rate is just subtracting apples from oranges (or, say, pomegranates in this case).
Just a caveat to my previous comment. There's one case in which subtracting inflation from GDP growth could be useful and, yes, would confirm Prof. Cole's assessment: if the reported GDP growth is NOMINAL GDP growth. But I'd be surprised if that's the case. Nominal GDP growth is a largely useless statistic that most economic agencies know not to puff up. Whenever it's reported, they immediately report the deflated GDP growth, because they understand that's the one we should care about. I know nothing about how Iranian economic agencies produce their statistics, or what are Prof. Cole's sources, but I would be very surprised if they simply reported the nominal GDP growth. If the 4% in the piece is nominal, then my previous comment is wrong. But it would be unusual if the stats agencies just reported that.
With all due respect to Prof. Cole, from whom I've learned a lot, the economic analysis of this piece is dead wrong. (I'm an economist, FWIW.) You don't simply subtract inflation from growth to determine real changes in purchasing power. If you want to get "real GDP growth" you subtract population growth from GDP growth. If you want to use inflation as a gauge of purchasing power you would have to use some other statistic, say, for instance, the change in the minimum wage (or average wage if that's available). But inflation by itself doesn't tell much about the change in the population's purchasing power. 4% of GDP growth and 9% inflation is not exactly an economic calamity. That inflation level is a bit too high, especially given the anti-inflation hysteria of many policy circles in the last years. But it's not in itself a huge issue. It is perfectly possible to have a well-functioning economy with those levels of inflation. The one caveat is to avoid it from spiraling, but 9% doesn't need to be the start of a spiral. Many economies have managed that. The 4% growth isn't bad either. It's mediocre, to be sure, especially considering Iran is a Third World country that should be growing more, but it's not bad either. And, to reiterate, subtracting the inflation rate from the growth rate is just subtracting apples from oranges (or, say, pomegranates in this case).