Quote from achilles28:
To elaborate..
Currency values are based on relative levels of purchasing power, where pp is determined by credit cycles in each host country.
High credit growth is characteristic of expansionary conditions, which is inflationary and erodes purchasing power, which depreciates a currency relative to a slow(er) growth nation.
Conversely, during recessions and depressions, credit destruction takes hold, which leads to price deflation, which is synonymous with increased purchasing power, which appreciates a currency's value.
That general relationship was easy to chart and track before the advent of globalization where regional and national economic cycles were largely asynchronous and independent. Globalization synchronized most economies making it difficult to see the relationship since most economies - and therefore, currency values - go up or down together.
What happened in Japan is largely what Ed Breen mentioned. Huge swaths of Government, business and consumer assets were wiped out. Assets are the basis for debt, or new loans. And since hundreds of billions in dollars in assets were wiped out, a corresponding downtick in loan creation will result. In other words, a good chunk of the collateral needed to finance the prior level of loan creation no longer exists....! Which fuels net credit destruction (relative to the trend up until last week), which is deflationary, which increases the purchasing power of the Yen, which appreciates it against the USD. Of course, the GOJ and BOJ has intervened and printed to stave off another round of deflation, but that's the general theme and explains why the market reacted the way it did.
In a way, the economic impact of the quake is similar to the housing collapse. Over a few months, the balance sheet of middle America took a 30-50% haircut. That 30-50% reduction in fungible assets, reduced their borrowing capacity by a similar amount, fueling credit destruction, and rebounding the US dollar. Of course, the flight to safety trade plays a huge role. But an appreciating greenback would have occurred regardless.
Well explained.