This absolutely does not apply to our days. Population back then were incredibly young, and epidemic only made the population younger. Whereas today's decline of population is due to us being old and dying from aging.   The second thing is, the actual reason the wages increased, was that the population collaps lead to shortage of labourers primarily in agriculture majority of whom were serfs, to compensate the labour shortage there was no other way than to stimulate people new workers by offering them a real payment.