It is said from early effect that with increase in collector to base voltage there is decrease in base width due to which \$\alpha\$ (the current gain) increases due to lesser recombination of holes and electron, so with increase in \$\alpha\$ emitter current should decrease according to equation
$$I_E=\frac{I_C}{\alpha} \, .$$
Also, concentration gradient of minority charge carriers in base region increases and due to which more majority charge carriers (of emitter region) come from emitter to base region and hence increasing emitter current.
Both of these effects are in contradiction to each other, so does it happen like latter effect is more than the former?
Best Answer
Not sure this will help you, but it helps me to understand that the metaphorical "bridge" that the collector current is crossing is both shorter in length (your first effect) and steeper (your second effect).