Some economists consider that increasing the minimum wage will have a negative effect on the level of employment.

1. Use a graph and words to explain how minimum wage can have a negative effect to the level of employment of low-skilled and young workers.
2. However, some economists, like David Card and Alan Krueger, have shown that this relation is not empirically proven. Could you think of at least two elements that could explain the fact that in some cases the minimum wage would not necessarily have a negative effect at the level of employment?