Hi Klaus, I tracked down the wage data for you. Also keep in mind that when I use "wages" I am using it broadly to mean "share of national income retained by households/workers/employees" (as opposed to companies or the government) which the Hartz reforms reduced through measures such as reduced welfare as well, but broadly speaking saying wages is accurate at least colloquially I think.

Here is the steep decline in German wages relative to productivity (meaning the share of German production retained by households declined) starting in 2003, source OECD (it's a screenshot of an OECD graph, can't find the original OECD link but OECD is listed as the source:

https://anticap.files.wordpress.com/2015/02/screen-shot-2013-05-14-at-12-33-06-pm.png

Here is a steep INCREASE in German corporate profits starting at the same time--2003 (source Deutsche Bundesbank via www.tradingeconomics.com):

https://anticap.files.wordpress.com/2015/02/germany-profits.jpg

As I've mentioned in other posts, the German household savings rate has more or less been constant at 10% for decades

https://tradingeconomics.com/germany/personal-savings

while consumption as a share of Germany's GDP declined from 56% in 2003 to 52% today, indicating the overall share of GDP retained by households declined (strangely, household share of GDP itself is not a statistic that is easy to find publicly, apparently, but obviously the math is clear if savings stays steady but consumption declines since those are the two possible uses for households):

https://www.theglobaleconomy.com/Germany/household_consumption/

Finally, the German trade surplus began increasing sharply also starting in... 2003, source below from the German Federal Statistics Office:

https://tradingeconomics.com/germany/balance-of-trade

So the overall story these numbers are telling is that starting/increasing from the Hartz reforms of 2003, national income was transferred via those reforms from households to companies, whose costs were then lower, which made their products cheaper internationally, enabling them to sell more and earn more profit, and at the same time Germany was able to import less (since household income was down and households are the largest net importers in any country), so the trade surplus went sharply up.

Since by definition every country cannot be an exporter, this economic composition cannot be copied by all countries, and it is also unsustainable (since other countries must go into debt in order to buy more than they sell to Germany, often by being lent back by German banks the extra corporate dollars earned by German companies due to these policies--see massive German lending to Southern Europe pre-crisis, and also German purchases of MBS's/CDO's from the US pre-crisis).

Note that to me the story these data tell is not anti-German, far from it, it's just that what they call for is a more pro German WORKER policy, as opposed to German corporation or financial institution. The share of national income which ordinary people retain must go up, which would increase German demand and hence imports, while decreasing exports, hence rebalancing to an extent the world economy, while also making German workers better off (although only to the extent that other countries don't then adopt a beggar thy neighbor, lower household income strategy). China of course has a far more imbalanced economy than even Germany (consumption is just 38% of GDP in China, the household share of GDP only about 50%), so it is even more urgent that China rebalance, but it is also an issue for Germany (especially with regards to the EU, and also the Western alliance internal relations).

Finally, I'll share if you're interested to follow up on your own that the experts I read who explained this most clearly and countered the opposite arguments clearly and hence convinced me (the most common opposite argument being the free market ideology that success in the global markets/exports/trade surpluses must be because you are "competitive" with no regards for domestic composition of national income) were Bernanke (he calls it the global savings glut, i.e. too much savings/corporate profits and nowhere to invest due to lack of demand due to low household share of income), Larry Summers (secular stagnation, he calls it), Olivier Blanchard (former chief economist of the IMF I think), Krugman (gives great summaries of changes in macroeconomic thought and its "financialization" since the 1980's), and Michael Pettis (former head of Bear Stearns bond trading during the AFC, now professor at Peking University).

Behind them all of course is Keynes with his focus on demand. In my view what is needed is a grand agreement among all countries, ideally, but certainly within the Western alliance (as China has been unable to increase its consumption share of GDP very much despite a lot of talk) to be aware of this issue and balance their economies and currencies so that these kinds of imbalances don't occur.