The emerging shortage of teachers in a growing number of districts and subject areas has cast a cold light on the numerous challenges facing the teaching profession. These include salaries that are much lower than those in jobs or professions that require as much or less academic preparation, an expectation that teachers can mitigate the impact of income levels and neighborhood conditions on academic performance, and the dwindling amount to time teachers have for professional learning and collaboration with other teachers. EdSource examines these challenges — and what can be done to overcome them.