In the context of certain dynamic models of monopsony, it is possible to infer the
elasticity of labor supply to the firm from the elasticity of the quit rate with respect to the wage.
Using this property, we estimate the average labor supply elasticity to public school districts in
Missouri. We take advantage of the plausibly exogenous variation in pre-negotiated district
salary schedules to instrument for actual salary. Instrumental variables estimates lead to a labor
supply elasticity estimate of about 3.65, suggesting the presence of significant market power for
school districts, especially over more experienced teachers. This is partially explained by
institutional features of the teacher labor market.

Wales and Woodland (1983) have proposed an econometric model to
deal with non-negativity constraints in systems of demand equations.
This paper points out the relationship between the Wales—Woodland model
and the "simultaneous Tobit" model of Amemiya (1974). This relationship
is important because Amemiya has proposed a simple estimation procedure
that can be utilized for some cases of the Wales—Woodland model. The
issue of internal consistency for models of this type is discussed. I
point out that internal consistency for the Wales—Woodland model is
equivalent to the second order condition for systems without quantity
constraints.

According to the family utility function approach, the labor supply
functions of married men should differ according to whether or not their
wives also work. In this paper I explicitly model the switching nature
of labor supply while also accounting for the endogeneity of the labor
force participation decision of the wife, using an endogenous switching
regressions model based on the quadratic family utility function. The
model is estimated from a cross-section of 1210 married couples from the
Panel Study of Income Dynamics.