The base index for the 2011-2012 school year is 1.4 percent, but it can be adjusted higher, depending on a number of factors, such as property values and the personal income of district residents.

This consisted of building monasteries and religious monuments, donating property such as the income of villages for the support of monks, and protecting previously donated property by leaving them exempt from taxation.

"When you look at economic issues, such as the income differential between workers and their bosses, you find tremendous inequality in America today, and inequality is rising," Professor Zweig said.

The Act 1 Index can be adjusted higher, depending on a number of factors, such as property values and the personal income of district residents.

For instance, the NBER considers not only the product-side estimates like GDP, but also income-side estimates such as the gross domestic income (GDI).