Nationale CO2-Steuer? Nicht vergessen: Österreich ist eine kleine offene Volkswirtschaft

In ihrem Bestreben Österreichs CO2-Emissionen zu senken, denken offenbar manche Experten (sowie auch einige Mitglieder der neuen türkis-grünen Regierung) an die Einführung einer nationalen CO2-Steuer.

Abgesehen von den Schwierigkeiten eine neue Steuer politisch zu verkaufen, gibt es da noch ein volkswirtschaftliches Problem: Österreich ist eine kleine offene Volkswirtschaft.

Na potzblitz! Max erzählt uns immer wieder was Neues, denken Sie sich jetzt. Aber wo liegt da das Problem?

Das Problem ist, kurz gefasst, dass die Wirkung eines CO2-Steuer in einer KOV radikal anders ausfällt als in einer geschlossenen Wirtschaft.

Man rufe sich folgendes Schaubild in Erinnerung:  

Wirkung einer CO2-Steuer in einer kleinen offenen Volkswirtschaft

Eine CO2-Abgabe erhöht die (Grenz-)Kosten der Produktion von CO2-intensiven Gütern wie Strom, Stahl, Papier, chemische Erzeugnisse, etc. Die Angebotskurve dieser Güter verschiebt sich daher nach links (von S auf S’). In einer geschlossenen Wirtschaft würde dies zu einem Anstieg im Preis und einen Rückgang in der Produktion und im Verbrauch dieser Güter führen. Und wenn wenigler Strom, Stahl, Papier, etc. produziert wird, sinkt auch der CO2-Ausstoß. Das ist die Standard-Logik der CO2-Steuer.

Aber in einer KOV wird der Preis nicht im Inland bestimmt, sondern am internationalen Markt. Eine CO2-Steuer führt nicht zu einem Anstieg im Preis CO2-intensiver Güter. Sie bewirkt einen Rückgang in der heimischen Produktion (von S* nach S’), aber nicht im Verbrauch (D*). Jede Tonne Stahl, jede Kilowattstunde Strom, jedes Blatt Papier, das in Österreich aufgrund der CO2-Steuer weniger produziert wird, wird durch erhöhte Netto-Importe ersetzt.

Was passiert mit den CO2-Emissionen?

Die Antwort hängt davon ab, ob man die CO2-Emissionen produktionsbasiert oder konsumbasiert betrachtet. Erstere gehen eindeutig zurück. Allerdings sind für das Klima die konsumbasierten Emissionen entscheidend. Schließlich ist dem Klima nicht geholfen, wenn Österreichs Industrie seine Emissionen um X Tonnen senkt, aber dafür X Tonnen mehr auf anderen Ländern importiert.

Ob die konsumbasierten CO2-Emissionen durch die CO2-Steuer steigen oder sinken hängt wiederum davon ab wie CO2-intensiv die Erzeugung von Strom, Stahl, Papier, etc. im Ausland ist. Hierzu empfiehlt sich die Lektüre von Karl Steininger und Pablo Muños (2010):

„Results show that during 1997 CO2 responsibility based on CBP [consumption based principle] were 36% larger than those based on PBP [production based principle]. This relation has increased through time. The CBP indicator of 2004 was 44% larger than the PBP. In terms of carbon emission location, for each Euro spent on Austrian final demand in 2004, it is estimated that two-thirds of the CO2 emissions occur outside Austrian borders.“

Soll heißen: Österreich ist klar ein Netto-Importeur von CO2-Emissionen.

Weil also eine nationale CO2-Steuer die Netto-Importe von CO2-intensiven Gütern erhöht und diese Güter im Ausland mehr Emissionen erzeugen als im Inland, kann man schließen, dass die konsumbasierten Emissionen Österreichs durch die Steuer steigen anstatt zu sinken.

(Die Anwendung einer CO2-Steuer auf eine große offene Volkswirtschaft bleibt dem geneigten Leser überlassen!)

(Ceterum censeo: I still think the demand side is the wrong side. Effective climate policy must restrict the supply of fossil fuel!)

A Tale of Two Energy Policies: Germany vs. UK

Some people have recently pointed out that one of the many adverse effects of Brexit is the fact that it makes it much harder for the European Union to hit its carbon emissions target. The reason is that the United Kingdom has the lowest per-capita emissions of carbon dioxide in the EU. So if the UK falls out of the EU statistics and the target doesn’t get adjusted, other EU countries will have to step up their emission reduction efforts.

This is, of course, more a problem of political symbolism than a substantial one: If member states thought that their pre-Brexit climate policies balanced the cost and benefits of emission reduction, then why should Brexit make a difference? What matters for the greenhouse effect, after all, are global emissions.

But one might ask: how come the UK is the “green poster child” of Europe? What are they doing differently? Here I find it instructive to compare the UK to Germany.

As is well-known, Germany has embarked on an ambitious policy of “energy transition” (Energiewende) which consists of a combination of subsidies for renewables and legally mandated targets for fossil energy production. (For reasons that don’t really make sense except to those living in the bubble of German public opinion, they also see their shutting down nuclear power plants as a part of the green energy transition.) The question of how fast the government should shut down coal plants, and other aspects of the energy transition, are hotly debated issues in Germany.

The UK has taken a different approach. Rather than trying to regulate the energy mix directly, the British government decided to use the price mechanism: they implemented a special tax to create a price floor for EU emission certificates which British energy producers need to buy. The price floor increases every year according to a fixed formula, ensuring that the cost to energy producers of emitting carbon dioxide in the UK has been substantially higher than in the rest of the EU throughout the last decade.

OK. So how did the UK do compared to Germany?

Pretty impressive. True, the UK’s per-capita emissions were lower than Germany’s to begin with. But Germany has cut their emissions by 12% over the last decade, while the UK cut theirs by 33%!

What about the energy mix?

The UK started from a renewable share of only 1.6% in 2007. Now it’s 11%. By contrast, during the same time, Germany went from about 10% to 16.5%. That, too, is a pretty impressive difference.

But didn’t the UK policy lead to much higher energy prices for consumers?

Nope. In fact, energy is considerably cheaper in the UK than in Germany. One kilowatt-hour of energy costs only about 18 euro cents in the UK (accounting for purchasing power differences and including all taxes) compared to 29 euro cents in Germany.

I call this a big win for Pigou taxes as opposed to direct regulation.

(Ceterum censeo: I still think the demand side is the wrong side. Effective climate policy must restrict the supply of fossil fuel!)

Addendum: Patrick Mellacher wants me to include the size of the industrial sector in my comparison. I’m happy to oblige him. Of course, the industrial sector is smaller in the UK compared to Germany. But that only explains why the level of emissions per capita is lower in the UK, not why the decrease in emissions was larger. It doesn’t seem like the industrial sector has changed in size (compared to the economy as a whole):

Intro to Econ: Eleventh Lecture Aside – Why don’t we have a global carbon tax?

If I understood it correctly, we are currently experiencing climate change, climate change is believed to be detrimental to most people, and climate change is to a large extent due to human activity, especially those activities that release CO2 and similar gases into the atmosphere. Moreover climate change is a global problem. Any CO2 released by people’s activities in Asia, this (supposedly mostly negatively) affects not only people in Asia, but also in South and North America, Africa, Australia, Europe, in fact everyone living on this planet. In other words, using the language of a previous post, climate change is a global negative externality of any economic activity that (directly or indirectly) releases CO2 (or similar gases) into the atmosphere.

In the last post I argued that such negative externality problems (that the market typically does not solve because of the logic explained in the advertising example) can often be solved by setting appropriate taxes on the offending (negative externality producing) products. I also argued that one would probably expect that a voting process will in fact lead to a country adopting such taxes. Can’t we just use a similar approach to solve the global climate crisis? I will here explain why this is not so easy.

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