At secondary level, where pupils have benefited from the pupil premium for a much smaller proportion of their schooling, it is much harder to compare progress because so much has changed in the exam system.
Another shortcoming is this makes it much harder to compare the prices and benefits of insurance offered by multiple companies, which is supposed to be one the biggest advantages of the exchanges.
You can understand why politicians like using total GDP, given it always grows by a bigger number, and it is much harder to fall compared with GDP per capita: In GDP per capita terms, Australia definitely did have a recession during the GFC, though we can still get comfort from the fact that our decline in 2008-09 was the second smallest in the advanced economic world, behind only South Korea.
This is bound within the cell walls and it is much harder to extract compared to free absorbed water, flowing through the vascular structures.
Also, good all-or-none results are much harder to achieve compared to results that measure outcomes using partial completion of indicators.
Also, NK models are much harder to work with; compare Obstfeld-Rogoff with Mundell-Fleming, and you're going from simple diagrams to 60-plus-equation derivations.
However, the logic of the MLP dictates that this will be much harder, and will take longer, compared to when windows of opportunities emerge in the regime.
The OLED screen is much harder to see in daylight when compared to the iPhone's screen.
