This paper studies the determinants of self-employment in Québec and in the rest of Canada by focusing on liquidity constraints, age and aggregate unemployment. We use a random effects probit model to analyse panel data from the Survey of Labour and Income Dynamics (SLID) for the period 1993-2010. The main results are as follows. The positive effect of investment income on the probability of being self employed confirms the existence of liquidity constraints. Being older increases the probability of choosing self-employment, rather than salaried work. This suggests that working for oneself may be a stepping stone towards retirement. High unemployment decreases the probability of being self-employed, suggesting that pull factors dominate push factors.