Confusões sobre a Estagnação Secular

Nos últimos tempos tem-se falado cada vez mais da Estagnação Secular, um conceito cunhado há quase 80 anos e ressuscitado em 2013 por Larry Summers. Nas suas linhas gerais, a ideia anuncia um futuro distópico para as economias desenvolvidas: pouco (ou nenhum) crescimento, níveis de vida estagnados e crises económicas recorrentes.

Summers argumenta que este é, ou pode provavelmente ser, o futuro da maior parte dos países ricos. Em parte porque é mais ou menos isto que vemos quando olhamos à volta – e em parte, suspeito, porque o nome da coisa se presta bem a manobras de marketing – a ideia cravou os dentes no debate público e agora aparece recorrentemente na comunicação social. Mas a forma como o tema é abordado, quer na sua formulação, quer nas suas implicações, deixa muito a desejar.

Em particular, tornou-se habitual dizer que a Estagnação Secular é uma teoria acerca do ‘fim do crescimento’, um facto da nossa vida económica ao qual temos de nos resignar. Na verdade, é precisamente o contrário.

A Estagnação Secular explica por que é que o amadurecimento das economias – tomado um facto exógeno – pode conduzir a falhas recorrentes e persistentes na procura global. De acordo com a teoria, os mecanismos de mercado que durante mais de dois séculos foram suficientes para estabelecer o pleno emprego podem tornar-se cada vez mais ineficazes, exigindo o apoio de outras forças para tapar essa lacuna. E isso tem um remédio.

Mas sobre esta questão o melhor que posso fazer é reencaminhar para o excelente A tale of two stagnations, de Noah Smith.  Vão lá ler tudo, porque aqui só incluí alguns trechos.

The term “secular stagnation” has become a catch-all description for long-term economic pessimism. But it’s gotten confused with a very different idea — the technological stagnation hypothesis, proposed by economist Robert Gordon (and by Bloomberg View’s Tyler Cowen). These are two very different ideas. Both would lead to slow growth in the long term, but they imply different causes and different remedies.

Summers’ secular stagnation is all about aggregate demand. Normally, economists think of demand as something that falls temporarily in a recession and then bounces back. But the failure of many economies to return to their previous trends after big slowdowns has made some economists worry if demand shortfalls could be very persistent.

Demand gaps usually emerge when everyone tries to save money at the same time. This could happen because people become more pessimistic about the future, for example, or because they suddenly decide they need more liquid assets. But when everyone tries to hold onto cash, they don’t spend, and so companies don’t produce things. Companies that don’t produce things lay off workers, and pretty soon there’s a recession.

Usually this process ends naturally. Eventually people need to replace their old cars and fix up their houses, or their temporary bout of pessimism ends, or some other force acts to restore demand. But under certain conditions, in some models, it’s possible for an economy to trap itself, so that low demand and slow growth become a self-reinforcing, self-perpetuating cycle.

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Technological stagnation is a different beast. According to Gordon and others, humanity has simply picked most of the low-hanging fruit of science and technology. Airplanes and cars travel no faster today than they did 50 years ago. Electricity, air conditioning and household appliances have made our homes about as pleasant as they’re likely to get, and so on. That doesn’t mean advances stop, but it means that each one is less game-changing than the last.

A key piece of the tech stagnation hypothesis is that production of the things we want isn’t going to get much cheaper. Gordon points to slowing productivity as evidence that our economy is getting worse at finding new ways to do more with less. This trend is worldwide, which makes sense, since a decline in science and technology should be global in nature.

So technological stagnation is all about supply, while secular stagnation is about demand. The two are related — slower productivity growth tends to reduce interest rates, putting the economy closer to the zero lower bound that drives demand shortages. But the two types of stagnation are very different things, requiring very different policy responses.

If we’re in secular stagnation, the economy is wasting its potential. Workers are staying home — not counted as officially unemployed, but out of the labor force completely — playing video games while offices sit empty and unused. In that case, we need something like fiscal stimulus to raise demand and lift us back to full employment.

But if we’re in technological stagnation, there’s not much we can do. Yes, there are some things government can do to boost innovation at the margin, like reforming patent laws, lifting onerous regulations, and investing in research and development. But in the long term, the forces of progress are difficult to predict and control. If we’ve already exploited the biggest innovations, we need to reconcile ourselves to living lives not much better than those of our parents. That would be a disappointing outcome, but it might be the best we can do.