This paper presents three sets of results about equilibrium bias of technology. First, I show that when the menu of technological possibilities only allows for factor-augmenting technologies, the increase in the supply of a factor induces technological change relatively biased toward that factor—meaning that the induced technological change increases the relative marginal product of the factor becoming more abundant. Moreover, this induced bias can be strong enough to make the relative marginal product of a factor increasing in response to an increase in its supply, thus leading to an upward-sloping relative demand curve. I also show that these results about relative bias do not generalize when more general menus of technological possibilities are considered. Second, I prove that under mild assumptions, the increase in the supply of a factor induces technological change that is absolutely biased toward that factor—meaning that it increases its marginal product at given factor proportions. The third and most important result in the paper establishes the possibility of and conditions for strong absolute equilibrium bias—whereby the price (marginal product) of a factor increases in response to an increase in its supply. I prove that, under some regularity conditions, there will be strong absolute equilibrium bias if and only if the aggregate production function of the economy fails to be jointly concave in factors and technology. This type of failure of joint concavity is possible in economies where equilibrium factor demands and technologies result from the decisions of different agents.

We develop a tractable framework for the analysis of the relationship between contractual incompleteness, technological complementarities, and technology adoption. In our model, a firm chooses its technology and investment levels in contractible activities by suppliers of intermediate inputs. Suppliers then choose investments in noncontractible activities, anticipating payoffs from an ex post bargaining game. We show that greater contractual incompleteness leads to the adoption of less advanced technologies, and that the impact of contractual incompleteness is more pronounced when there is greater complementary among the intermediate inputs. We study a number of applications of the main framework and show that the mechanism proposed in the paper can generate sizable productivity differences across countries with different contracting institutions, and that differences in contracting institutions lead to endogenous comparative advantage differences. (JEL D86, O33)

We exploit the major international health improvements from the 1940s to estimate the effect of life expectancy on economic performance. We construct predicted mortality using preintervention mortality rates from various diseases and dates of global interventions. Predicted mortality has a large impact on changes in life expectancy starting in 1940 but no effect before 1940. Using predicted mortality as an instrument, we find that a 1 percent increase in life expectancy leads to a 1.7-2 percent increase in population. Life expectancy has a much smaller effect on total GDP, however. Consequently, there is no evidence that the large increase in life expectancy raised income per capita. (c) 2007 by The University of Chicago. All rights reserved.