Consider a model of the American economy where the level of income (Y) is produced with two factors of production, land (X)
and labor (L).
Y = X^AlphaL^Beta
Suppose land's share of income is Alpha = 0.5 and labor's share of income is Beta = 0.5. If the level of income grows at a rate of 6% per annum, land stock grows at a rate of 2%, and labor supply grows at a rate of 2%, the rate of total factor productivity growth is: