Empirical studies have found that enhanced foreign competition can encourage or discourage innovation. To address this relationship, I examine a market structure in which a small number of large multi-product oligopolists compete with a large number of small single-product firms in the same...

History and theory alike suggest that General Purpose Technologies (GPT's), such as the steam engine or electricity, may play a key role in economic growth. In a previous paper (Helpman and Trajtenberg, 1994) we incorporated this notion into a Grossman-Helpman growth model, and explored the...

We develop a model of growth driven by successive improvements in 'General Purpose Technologies' (GPT's), such as the steam engine, electricity, or micro-electronics. Each new generation of GPT's prompts investments in complementary inputs, and impacts the economy after enough such compatible...

Forward-looking investments determine the resilience of firms' supply chains. Such investments confer externalities on other firms in the production network. We compare the equilibrium and optimal allocations in a general equilibrium model with an arbitrary number of vertical production tiers....

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....

We characterize trade policies that result from political competition when assessments of well-being include both material and psychosocial components. The material component reflects, as usual, satisfaction from consumption. Borrowing from social identity theory, we take the psychosocial...

We generalize the Antras and Helpman (2004) model of the international organization of production in order to accommodate varying degrees of contractual frictions. In particular, we allow the degree of contractibility to vary across inputs and countries. A continuum of firms with heterogeneous...

Misinformation pervades political competition. We introduce opportunities for political candidates and their media supporters to spread fake news about the policy environment and perhaps about parties' positions into a familiar model of electoral competition. In the baseline model with full...

We develop a model of large multinational enterprises, each one producing a continuum of products. These outsized firms compete as oligopolists in a domestic and foreign market, facing competitive pressure from single-product firms that engage in monopolistic competition. The multinational...

Supply chain disruptions, which have become commonplace, are often associated with globalization and trade. Little is known about optimal policy in the face of insecure supply chains. Should governments promote resilience by subsidizing backup sources of input supply? Should they encourage firms...