Why did Emperor Ferdinand I abdicate in favour of Franz Joseph?

Emperor Ferdinand I abdicated the throne on December 2, 1848, in favor of his nephew, Franz Joseph, during the Revolution of 1848.

While Ferdinand’s reign was marked by his limited abilities and reliance on a "state conference" of counselors—most notably Klemens, prince von Metternich—the primary impetus for his abdication was the widespread political unrest of 1848. Although the insurgents' hostility was directed largely at his counselors for their rigid refusal to implement reforms, the political climate necessitated a change in leadership. By passing over the rights of his brother, Archduke Francis Charles, and abdicating to the young Franz Joseph, the monarchy hoped to restore stability and revive monarchist sentiment through the new emperor's youthful appearance.12