Perfectly competitive innovation
We construct a competitive model of innovation and growth under constant returns to scale. Previous models of growth under constant returns cannot model technological innovation. Current models of endogenous innovation rely on the interplay between increasing returns and monopolistic markets. In fact, established wisdom claims monopoly power to be instrumental for innovation and sees the nonrivalrous nature of ideas as a natural conduit to increasing returns. The results here challenge the positive description of previous models and the normative conclusion that monopoly through copyright and ...
Factor saving innovation
We study a simple model of factor saving technological innovation in a concave framework. Capital can be used either to reproduce itself or, at additional cost, to produce a higher quality of capital that requires less labor input. If higher quality capital can be produced quickly, we get a model of exogenous balanced growth as a special case. If, however, higher quality capital can be produced slowly, we get a model of endogenous growth in which the growth rate of the economy and the rate of adoption of new technologies are determined by preferences, technology, and initial conditions. ...
IER Lawrence Klein Lecture: the case against intellectual monopoly
In the modern theory of growth, monopoly plays a crucial role both as a cause and an effect of innovation. Innovative firms, it is argued, would have insufficient incentive to innovate should the prospect of monopoly power not be present. This theme of monopoly runs throughout the theory of growth, international trade, and industrial organization. We argue that monopoly is neither needed for, nor a necessary consequence of, innovation. In particular, intellectual property is not necessary for, and may hurt more than help, innovation and growth. We argue that, as a practical matter, it is more ...
Reconstructing the great recession
This paper evaluates the role of the construction sector in accounting for the performance of the U.S. economy before, during and after the Great Recession. We use input-output analysis to evaluate its linkages with the rest of the economy and measure the transmission of its demand shocks to the overall economy. Such effects are quantified by means of a dynamic multi-sector model parameterized to reproduce the boom-bust dynamics of employment in construction during 2000-13. The model suggests that the interlinkages account for a large share of the actual changes in aggregate employment and ...
What happened to the US stock market? Accounting for the last 50 years
The extreme volatility of stock market values has been the subject of a large body of literature. Previous research focused on the short run because of a widespread belief that, in the long run, the market reverts to well understood fundamentals. Our work suggests this belief should be questioned as well. First, we show actual dividends cannot account for the secular trends of stock market values. We then consider a more comprehensive measure of capital income. This measure displays large secular fluctuations that roughly coincide with changes in stock market trends. Under perfect foresight, ...
Habit persistence, asset returns and the business cycles
We introduce two modifications into the standard real business cycles model: habit persistence preferences and limitations on intersectoral mobility. The resulting model is consistent with the observed mean equity premium, mean risk free rate and Sharpe ration on equity. With respect to the conventional measures of business cycle volatility and comovement, the model does roughly as well as the standard real business cycle model. On four other dimensions its business cycle implications represent a substantial improvement. It accounts for (i) persistence in output, (ii) the observation that ...
Asset pricing lessons for modeling business cycles
Habit persistence and asset returns in an exchange economy
We examine asset prices and returns in the context of a version of the pure exchange economy studied in Lucas (1978) and Mehra and Prescott (1985). Our purpose is to identify the key channels by which changes in preferences affect the equity premium and the risk free rate and to develop intuition that is useful for understanding asset pricing in more complicated economies. Our analysis suggests that capital gains play a crucial role in generating empirically plausible mean equity premia.
Intellectual property and market size
Intellectual property protection involves a trade-off between the undesirability of monopoly and the desirable encouragement of creation and innovation. As the scale of the market increases, due either to economic and population growth or to the expansion of trade through treaties such as the World Trade Organization, this trade-off changes. We show that, generally speaking, the socially optimal amount of protection decreases as the scale of the market increases. We also provide simple empirical estimates of how much it should decrease.
Fertility and Social Security
The data show that an increase in government provided old-age pensions is strongly correlated with a reduction in fertility. What type of model is consistent with this finding? We explore this question using two models of fertility: one by Barro and Becker (1989), and one inspired by Caldwell (1978, 1982) and developed by Boldrin and Jones (2002). In Barro and Becker's model parents have children because they perceive their children's lives as a continuation of their own. In Boldrin and Jones' framework parents procreate because children care about their parents' utility, and thus provide ...