In doing so, we have controlled for possible effects of differences in educational inputs such as class sizes, availability of materials, and aggregate expenditure per student in the country. (educationnext.org)
And it is wrong by standard definitions, where aggregate expenditure and income are the same thing, and investment and saving are also the same thing (for a closed economy, including government investment and saving). (worthwhile.typepad.com)
There are a few exceptions: The settlement allows publishers the option to negotiate retailer contracts that include «a commitment from an e-book retailer that a retailer's aggregate expenditure on discounts and promotions of the Settling Defendant's ebooks will not exceed the retailer's aggregate commission» — though that doesn't prevent deep discounts on specific titles. (gigaom.com)