Does effort require to pedal depend on the gear ratio or the gear inches?
Gear inches. Gear inches are, for better or worse, the most commonly recognized way of making the kind of comparison you're trying to make here, which one is harder to pedal. Gear inches are simply how far one complete rotation of the cranks moves the bike forward. The higher the number, the harder it is to turn the cranks.

You hear people make reference to ratio all the time, but usually it's within a niche where the wheel size is implicit, i.e. cross racers talking about 46/11 on a 700 or BMXers and 25/9 on a 20". Gear ratio independent of wheel size is meaningless. 

Gear inches are actually a deeply flawed concept because it doesn't account for crank length. Sheldon Brown's proposed Gain Ratios system solves this and is pretty easy to argue as the best system possible for describing bicycle gearing. It's based on the movement of the pedal and not the crank.