Worthwhile Canadian Initiative: The mathematics generation gap.
Here's my theory: Some students struggle with economics because they do not fully understand the mathematical tools economists use. Profs do not know how their students were taught mathematics, what their students know, what their students don't know - and have no idea how to help their students bridge those gaps.
The arithmetic gap is the most obvious one: profs over a certain age (and some immigrant profs) were drilled in mental math; Canadian students under a certain age haven't been. Some implications of the arithmetic gap are familiar: profs who can't understand why students insist on using calculators; students who can't understand why their profs are so unreasonable.
But the mental arithmetic gap has more subtle implications. Mental calculations often require intuition about, and comfort with, the use of fractions. Pre-calculator: 1/3+1/3=2/3. Calculator era: 0.3333....+0.3333....=0.6666.... Pre-calculator: "To multiply by twenty-five, divide by four and add two zeros (25*Y=1/4*100*Y)" Calculator: Multiply by twenty-five. Back in the day, fractions were easier than - or at least not much more difficult than - decimals. Calculators make fractions obsolete. An economic concept that requires a deep understanding of how to use and manipulate fractions is elasticity: the percentage change in X/percentage change in Y. I wonder: how many students struggle with elasticity formulas because they struggle to manipulate and understand fractions?