Optimism among big Japanese producers soared to the highest level in four years in the third quarter on the back of improving earnings, reinforcing a view the world's third largest economy is strong enough to withstand the planned hike in consumption tax. Japanese Ministry of Finance unveiled a report showing the business survey index, or BSI, stood at +15.2 in July-September period, more than three times higher than 5.0 recorded in the previous quarter. This reading marks the highest level since the same quarter in 2009, another signs that widely discussed Abenomics are spreading across the country. The BSI index reflects the percentage of companies that expected the business conditions to improve in the upcoming months minus the number of companies that expect it to deteriorate. Meanwhile, this measure is expected to worsen slightly in the last quarter of this year, falling to 13.5.