August was a rough month for sharemarkets, investors and governments in Europe, Japan and the US. September is shaping as a replay with Australia, Europe and the US each facing a major test on at least one day in the next seven.

In fact next week has several trip points that could affect global markets, with one, next Wednesday night (our time) in Germany, capable of sending the global economy and markets into a swoon.

First up tonight, sentiment will be tested by the August US jobs and unemployment data: a feature of the past week has been the way forecasters have cut their estimates of new jobs for August from more than 100,000 to about 45,000 (Goldman Sachs overnight).

If the number of new jobs comes out at about 45,000, then it will be bad news, but markets might go phew, it could have been worse, and rise, such is the perverse nature of US sentiment at the moment. President Obama plans a big statement on the dire US jobs situation next week. It will be words, and more words (keeping his speech writers and advisers in jobs) and nothing else. America lacks demand, not output and Obama can’t provide that.

(The next big US test date is the two-day meeting of the Federal Reserve on September 20-21, which will feature a discussion on what the central is willing to do to further stimulate the economy: the best bet is it will start targeting longer-term rates at the 5%-10% range).

In Australia, there’s three test dates next week: Tuesday with the September Reserve Bank board meeting in Perth, Wednesday with the June quarter national accounts and a major speech in Perth that evening from RBA governor Glenn Stevens, and Thursday’s release of the jobs data for August.

Before then there’s some important data that will feed into the national accounts, which could be better than expected.

Some forecasters (such as the NAB), are predicting a quarterly growth rate of 0.9% for the three months to June. But there could be a significant revision to the March quarter figure, which showed a large 1.2% contraction. This idea of a revision follows a revision in the June quarter investment data from the Australian Bureau of Statistics.

While June quarter investment rose a solid 4.9% (with a 2.2% rise in investment in plant and buildings, which will feed through into the growth figures), the March quarter first estimate of 3.4% growth was more than doubled in the revision to a massive 7.7% jump. That was due to more investment being found in flood-affected Queensland.

And the capex figures show that while mining is planning investment to more than $80 billion this year, manufacturing is planning a 10.5% boost, to $13.1 billion of investment in the 2011-12 financial year. That’s also 7.4% more than the $12.2 billion estimated to have been spent in 2010-11 and about the average of the past five years, which belies much of the recent talk in the media and from some sections of manufacturing. Even retailing is down to spend about $4.13 billion in the 2012 financial year, down $64 million from the 2011 spend, which is an insignificant fall.

So there’s a suspicion that the first quarter growth contraction might not have been as deep. Retail sales grew by a stronger 0.5% in July, possibly a one off, or possibly a sign of a turn. Clothing, footwear and personal accessories took a hit, seeing a fall of 4.2% in the month. Retailers say wait for the August figures because many say spending fell last month.

The jobs data on Thursday are forecast to show a rise in the number of jobless after several companies cut jobs in June, July and August. Watch the 5.1% unemployment rate, if it doesn’t change, then perhaps the outlook isn’t as glum.

If the data falls the right way, by Friday we could be wondering and arguing over a a possible rate rise later in the year or early next year. At the moment, forecasters such as AMP Global’s Dr Shane Oliver see a rate cut by Christmas (the Melbourne Cup meeting in November is the best bet).

But while these dates in Australia and the US are important, next Wednesday in Germany is the big day.

Chancellor Angela Merkel has cancelled a trip to Russia on September 7 because that’s the day when the latest bailout package goes to the Bundestag and the country’s constitutional court rules on the legality of the EU’s bailout machinery.

If the court rules that the €440 billion rescue fund (the EFSF) breaches EU Treaty law or undermines German fiscal sovereignty, it risks setting off an instant bushfire across not only the eurozone, but the entire EU.

If that happens, then Germany will not be able to support the bailout fund, the bailouts of Ireland, Greece (2) and Portugal will be in doubt and the European Central Bank, which is currently supporting banks in Spain, Italy, Greece, Ireland, Portugal and other countries (and Spain and Italian sovereign debt at the moment) will be left high and dry and vulnerable.

If the vote is negative, it will set off a selling wave in debt and sharemarkets that would dwarf what we saw in the first two weeks of August.

If the German Constitutional court rules in favour of the bailout machinery’s legality, then this could be the mechanism that finally starts changing sentiment in favour of the euro and Europe, even though the various economies are dipping towards a slowdown.

By the way, the second bailout of Greece is hitting the wall, again. The country’s economy is in a deeper recession than previously thought, the budget deficit will be at least 8.6% of GDP, compared to a target of 7.6%. As well the IMF and EU inspectors found delays and shortcomings in implementing the bailout plan, which was beefed up in July by an EU agreement for a second bailout of more than €109 billion. Greece is in its third year of recession. It can’t pay its way out of any bailout.

If the German court finds against the bailout mechanism, it could be one of those “perfect storms” currently favoured by headline writers and market cliche writers.

PS: And by the way, the Australian market was “only” down 2.9% in August, which was the best performance of all major markets around the world. The US was down 4%-6%, European markets were down 7% to nearly 20%, Japan had a month worse than March when the quake and tsunami rattled confidence. But its remarkable that local pundits and have avoided this point. That this relative “outperformance” occurred during what was claimed to be a tough profit-reporting season, was also left mostly untouched by the critics.