Optimal prepayment and default rules for mortgage-backed securities

We study the optimal stopping problems embedded in a typical mortgage. Despite a possible non-rational behaviour of the typical borrower of a mortgage, such problems are worth to be solved for the lender to hedge against the prepayment risk, and because many mortgage-backed securities pricing models incorporate this suboptimality via a so-called prepayment function which can depend, at time t, on whether the prepayment is optimal or not. We state the prepayment problem in the context of the optimal stopping theory and present an algorithm to solve the problem via weak convergence of computationally simple trees. Numerical results in the case of the Vasicek model and of the CIR model are also presented. The procedure is extended to the case when both the prepayment as well as the default are possible: in this case, we present a new method of building two-dimensional computationally simple trees, and we apply it to the optimal stopping problem.     

Optimal installation of renewable electricity sources: the case of Italy

Decisions in Economics and Finance - Starting from the model in Koch and Vargiolu (SIAM J Control Optim 59(4): 3068–3095, 2021), we test the real impact of current renewable installed power...     

The wage and non-wage costs of displacement in boom times: Evidence from Russia

This paper analyzes the costs of job loss over the years of a booming economy, 2003–2008, using unique data from the Russian Longitudinal Monitoring Survey. In addition to analyzing standard labor market outcomes, such as forgone earnings, employment, hours worked and wage penalties, our unique data set allows us to investigate additional non-wage costs of displacement, in particular, fringe benefits, the propensity to have an informal employment relationship or a temporary contract. We find that displaced individuals face large foregone earnings following displacement, which are heterogeneous across education and ownership type of firm from which the worker separated. There is no evidence of wage penalties for re-employed displaced workers. However, we find an increased probability of working in informal or temporary jobs if previously displaced and a reduction in the number of benefits.     

Null models of economic networks: the case of the world trade web

In all empirical-network studies, the observed properties of economic networks are informative only if compared with a well-defined null model that can quantitatively predict the behavior of such properties in constrained graphs. However, predictions of the available null-model methods can be derived analytically only under assumptions (e.g., sparseness of the network) that are unrealistic for most economic networks like the world trade web (WTW). In this paper we study the evolution of the WTW using a recently-proposed family of null network models. The method allows to analytically obtain the expected value of any network statistic across the ensemble of networks that preserve on average some local properties, and are otherwise fully random. We compare expected and observed properties of the WTW in the period 1950–2000, when either the expected number of trade partners or total country trade is kept fixed and equal to observed quantities. We show that, in the binary WTW, node-degree sequences are sufficient to explain higher-order network properties such as disassortativity and clustering-degree correlation, especially in the last part of the sample. Conversely, in the weighted WTW, the observed sequence of total country imports and exports are not sufficient to predict higher-order patterns of the WTW. We discuss some important implications of these findings for international-trade models.     

A soaring eagle: Alfred Marshall 1842–1924 Peter D. Groenewegen Edward Elgar, 1995, 874 pp.

Since Keynes's masterful obituary, knowledge of Marshall's life has greatly increased. Family and social background, early philosophical and economic writings, and involvement with educational reforms are subjects on which readers now enjoy the benefits of better and more reliable information. By itself, this would have made an extensive biography worth its while Groenewegen's book goes much further, adding new discoveries, discussing Marshall's heritage, and endeavoring to provide a coherent whole in order to preserve "Marshall's social philosophy." Though digressions make it somewhat difficult to concentrate attention on any one connecting thread, the book offers a balanced and informed treatment of Marshall's life and activities. This article examines the book's merits and limitations and points out some hidden aspects of Marshall's character and research programs.     

Human resource management and industrial relations in Italy

Evolution of industrial relations and human resource management in Italy in the last decade is analysed through qualitative case studies, quantitative surveys and a combination of qualitative/quantitative data originating from network researches.

In the 1980s, complementary industrial relations/human resource management in Italy were based on the trade-off between employment security, work flexibility and industrial adjustment. In the 1990s this complementarity is under pressure from a second restructuring process (and privatization) of Italian enterprises.

The last surveys underline that the basic features of industrial relations were not altered, but the data confirm the critical importance of the relationship between industrial relations and human resource management and also the fragility of this balance.     

Whatever happened to Marshall's industrial economics?

Industry and Trade and the works on industrial economics by the Cambridge school – Chapman, Macgregor, Robertson, Lavington, A. Robinson and Florence – are usually neglected as if they were devoid of theoretical relevance. By contrast, the author argues that Marshall's evolutionary model, centred on the continuous interplay between innovation and standardization, inspired original research on localization, business size, coordination costs and industrial combinations. The paper also suggests that Marshallian ideas on the growth of firms and the structure of industrial organization are coming back in contemporary evolutionary theories of the firm.     

Optimal monetary policy under low trend inflation

In the monetary policy literature it is common to assume that trend inflation is zero, despite overwhelming evidence that zero inflation is neither empirically relevant nor a practical objective for central bank policy. We therefore extend the standard New Keynesian model to allow for positive trend inflation, showing that even low trend inflation has strong effects on optimal monetary policy and the dynamics of inflation, output and interest rates. Under discretion, the efficient policy deteriorates and there is no guarantee of determinacy. Even with commitment, targeting non-zero trend inflation leads to substantial welfare losses. Our results serve as a warning against indiscriminate use of models assuming zero trend inflation.