Portfolio Optimization in Discontinuous Markets under Incomplete Information

We consider the problem of maximization of expected utility from terminal wealth for log and power utility functions in a market model that leads to purely discontinuous processes. We study this problem as a stochastic control problem both under complete as well as incomplete information. Our contribution consists in showing that the optimal strategy can be obtained by solving a system of equations that in some cases is linear and that a certainty equivalence property holds not only for log-utility but also for a power utility function. For the case of a power utility under incomplete information we also present an independent direct approach based on a Zakai-type equation.      

New combinations in old industries

The literature on long waves gives great emphasis to the process of the diffusion of new pervasive technologies that raise productivity and growth, first in the sectors that generate them, then in those sectors that progressively adopt them. This paper explores this process of diffusion, relying on an ongoing analysis of the diffusion of robotized, modular production process in the international tire industry. The analysis captures three key features of the diffusion process of the long wave. First, we look at the emergence of radical innovations in mature sectors through the adoption of pervasive technologies, i.e. robotics. Second, we see that the adoption of the new process goes hand in hand with the adoption of new organizational routines at the level of both design and manufacturing processes, modularity. Third, this study highlights the role played by key individuals—entrepreneurs—who develop new ways of doing business.     

Nominal debt as a burden on monetary policy

We characterize the optimal sequential choice of monetary policy in economies with either nominal or indexed debt. In a model where nominal debt is the only source of time inconsistency, the Markov-perfect equilibrium policy implies the progressive depletion of the outstanding stock of debt, until the time inconsistency disappears. There is a resulting welfare loss if debt is nominal rather than indexed. We also analyze the case where monetary policy is time inconsistent even when debt is indexed. In this case, with nominal debt, the sequential optimal policy converges to a time-consistent steady state with positive—or negative—debt, depending on the value of the intertemporal elasticity of substitution. Welfare can be higher if debt is nominal rather than indexed and the level of debt is not too high.     

The impact of state legitimacy on entrepreneurial activity

The purpose of this research is to analyze the influence of the state legitimacy on of the different countries’ entrepreneurial activity’s development, the opportunities’ perception and the entrepreneurship’s motivations. This paper is set into the research field which analyze how the institutional environment influence entrepreneurship in different countries. Research framework has been built based on the Institutional Theory. To develop the model we use a set of data extracted from the European Social Survey and the Global Entrepreneurship Monitor about 28 European countries and we analyze them through Partial Least Squares-Structural Equation Modeling. Results show that state’s legitimacy influences the level of entrepreneurship in the different countries and the perception of the entrepreneurial opportunities and chances. Besides, the research shows that, in the scenario of the most legitimated countries, entrepreneurial activities is related to the need of self-employment. Based on the Institutional Theory, this research provide relevant contributions in the research field about entrepreneurship and countries’ institutions. From a practical point of view, the research shows ideas on how policymakers can improve entrepreneurial activity managing state legitimacy. Furthermore, the results provide new contributions in the research on the influence of the institutional context on the states entrepreneurial activity, providing an analysis and a comparison of the differences between countries, based on institutional theory.

     

Diverse twins: analysing China’s impact on Italian and German exports using a multilevel quantile regressions approach

Germany and Italy are the largest manufacturing producers in Europe and export over 70% of their products to OECD countries. While they share many characteristics, they are also diverse in term of specialization and destination markets. Italy has a productive structure largely based on labour intensive sectors, while Germany is mainly specialized in high-tech goods. We study whether these characteristics make the two countries vulnerable in different ways to the competitive pressure by emerging economies, especially China, which experienced the strongest increase in export market share during the last decades. We discuss the impact of China on the export performance of Italy and Germany on OECD markets. Using data for the period 1995–2009, we implement a novel model to account for two important data characteristics: their hierarchical hidden structure (captured by a multilevel model) and the heterogeneity of the export shares (captured by a quantile approach). Results show that Chinese competition on Italy’s and Germany’s market shares differ by sectors, but, on average, Italy is not more vulnerable than Germany. These results are relevant for policy implications and for an ex-post analysis of the ‘best response’ to the Chinese competition.     

Do mergers really increase output? Evidence from English hospitals

The English hospital sector underwent a major restructuring program between 2000 and 2008 to centralize activity in fewer and larger hospitals. The aim of this paper is to evaluate the effects of such consolidations on hospital outputs. As mergers occurred in a staggered way, treatment could start and end at every time and treatment duration varied over the years. As every time is a mix of hospital pre-treatment, treatment and post-treatment phases, the canonical difference-in-differences assumption of homogeneous policy effects is not only meaningless but also misleading, raising doubts about the appropriateness of the methods previously used in this literature and consequently the accuracy of its results. We instead adopt a new matching and difference-in-differences approach, the flexible conditional difference-in-differences approach, developed by Dettmann et al. in 2020, more appropriate for causal analysis of treatments characterized by varying start dates and varying treatment duration. Our results suggest that mergers downsize hospital activities, especially the most expensive ones. If the goal of hospital mergers is to gain efficiency by centralization of activity, our findings suggest this restructuring programme is not the most successful policy to pursue. Mergers reduce the scope for competition between hospitals and do not create any incentive for poorly performing hospitals.