Risk management in a mega-project: the Universal EXPO 2015 case

The paper analyses the literature on risk management in mega-projects suggesting possible mitigation actions to be considered in the stakeholders' management. EXPO 2015 represents a perfect project to understand the strength of a rigorous methodological approach to uncertainty and the need for a mature consciousness at managerial level on these topics. Analysing real available data on this project, the number of visitors appears overestimated, so, by adopting a framework, called SHAMPU, the paper quantifies the relative impact and provides possible mitigation actions. Practical actions crossing the risk management phases in mega projects proposed by literature are suggested in the conclusions

The large connectivity limit of bootstrap percolation

Bootstrap percolation provides an emblematic instance of phase behavior characterised by an abrupt transition with diverging critical fluctuations. This unusual hybrid situation generally occurs in particle systems in which the occupation probability of a site depends on the state of its neighbours through a certain threshold parameter. In this paper we investigate the phase behavior of the bootstrap percolation on the regular random graph in the limit in which the threshold parameter and lattice connectivity become both increasingly large while their ratio $\alpha$ is held constant. We find that the mixed phase behavior is preserved in this limit, and that multiple transitions and higher-order bifurcation singularities occur when $\alpha$ becomes a random variable.Comment: 6 pages, 4 figure

Weird Ties? Growth, Cycles and Firm Dynamics in an Agent-Based Model with Financial-Market Imperfections

This paper studies how the interplay between technological shocks and financial variables shapes the properties of macroeconomic dynamics. Most of the existing literature has based the analysis of aggregate macroeconomic regularities on the representative agent hypothesis (RAH). However, recent empirical research on longitudinal micro data sets has revealed a picture of business cycles and growth dynamics that is very far from the homogeneous one postulated in models based on the RAH. In this work, we make a preliminary step in bridging this empirical evidence with theoretical explanations. We propose an agent-based model with heterogeneous firms, which interact in an economy characterized by financial-market imperfections and costly adoption of new technologies. Monte-Carlo simulations show that the model is able jointly to replicate a wide range of stylised facts characterizing both macroeconomic time-series (e.g. output and investment) and firms' microeconomic dynamics (e.g. size, growth, and productivity).Financial Market Imperfections, Business Fluctuations, Economic Growth, Firm Size, Firm Growth, Productivity Growth, Agent-Based Models.

Are Output Growth-Rate Distributions Fat-Tailed? Some Evidence from OECD Countries

This work explores some distributional properties of aggregate output growth-rate time series. We show that, in the majority of OECD countries, output growth-rate distributions are well-approximated by symmetric exponential-power densities with tails much fatter than those of a Gaussian. Fat tails robustly emerge in output growth rates independently of: (i) the way we measure aggregate output; (ii) the family of densities employed in the estimation; (iii) the length of time lags used to compute growth rates. We also show that fat tails still characterize output growth-rate distributions even after one washes away outliers, autocorrelation and heteroscedasticity.Output Growth-Rate Distributions, Normality, Fat Tails, Time Series, Exponential-Power Distributions, Laplace Distributions, Output Dynamics.

Spatial Localization in Manufacturing: A Cross-Country Analysis

This paper employs a homogenous firms database to investigate industry localization in European countries. More specifically, we compare, across industries and countries, the predictions of two of the most popular localization indices, i.e., the Ellison and Glaeser (1997) index and the Duranton and Overman (2005) index. We find that, independently from the index used, localization is a pervasive phenomenon in all countries studied, but the degree of localization is very uneven across industries in each country. Furthermore, we find that the two indices significantly diverge in predicting the intensity of the forces generating localization within each industry. Finally, we perform a cross-sectoral analysis of localized industries. We show that, in all countries, localized sectors are mainly ``traditional'' sectors (like jewelery, wine, and textiles) and sectors where scale economies are important. However, once one controls for countries' industrial structures science-based sectors turn out to be the most localized ones.Industry Localization; Manufacturing Industries; Localization Indices; Spatial Concentration; Spatial correlation; Cross-country studies

How Do Output Growth Rate Distributions Look Like? Some Time-Series Evidence on OECD Countries

This paper investigates the statistical properties of within-country GDP and industrial production (IP) growth rate distributions. Many empirical contributions have recently pointed out that cross-section growth rates of firms, industries and countries all follow Laplace distributions. In this work, we test whether also within-country, time-series GDP and IP growth rates can be approximated by tent-shaped distributions. We fit output growth rates with the exponential-power (Subbotin) family of densities, which includes as particular cases both the Gaussian and the Laplace distributions. We find that, for a large number of OECD countries including the U.S., both GDP and IP growth rates are Laplace distributed. Moreover, we show that fat-tailed distributions robustly emerge even after controlling for outliers, autocorrelation and heteroscedasticity

How Much Does the UK Invest in Intangible Assets?

We attempt to replicate for the UK the Corrado, Hulten and Sichel (2005, 2006) work on spending on intangible assets in the US. Their work suggests private sector expenditure (investment) on intangibles is about 13% (11%) of US GDP 1998-2000, with intangible investment about equal to tangible capital investment. Our work, using a similar method, suggests the UK private sector spent, in 2004, about £127bn on intangibles, which is about 11% of UK GDP. The implied investment figure is around £116bn (10% of GDP) which is about equal to UK investment in tangible assets. Of the £127bn expenditure, (in round numbers) about 15% is spent on software, about 10% on scientific R&D, almost 20% on non-scientific R&D (design, product development etc.), about 14% on branding, about 20% on training and the rest on organisational capital.Intangible assets, R&D, Training, Organisational capital, Investment

What Happened to the Knowledge Economy? ICT, Intangible Investment and Britain's Productivity Record Revisited

A major puzzle is that despite the apparent importance of innovation around the "knowledge economy", UK macro performance appears unaffected: investment rates are flat, and productivity has slowed down. We investigate whether measurement issues might account for the puzzle. The standard National Accounts treatment of most spending on "knowledge" or "intangible" assets is as intermediate consumption. Thus they do not count as either GDP or investment. We ask how treating such spending as investment affects some key macro variables, namely, market sector gross value added (MGVA), business investment, capital and labour shares, growth in labour and total factor productivity, and capital deepening. We find (a) MGVA was understated by about 6% in 1970 and 13% in 2004 (b) instead of the nominal business investment/MGVA ratio falling since 1970 it is has been rising (c) instead of the labour compensation/MGVA ratio being flat since 1970 it has been falling (d) growth in labour productivity and capital deepening has been understated and growth in total factor productivity overstated (e) total factor productivity growth has not slowed since 1990 but has been accelerating.Intangible assets, Productivity, R&D, Training, Organisational capital, Investment

Income Distribution, Credit and Fiscal Policies in an Agent-Based Keynesian Model

This work studies the interactions between income distribution and monetary and fiscal policies in terms of ensuing dynamics of macro variables (GDP growth, unemployment, etc.) on the grounds of an agent-based Keynesian model. The direct ancestor of this work is the "Keynes meeting Schumpeter" formalism presented in Dosi et al. (2010). To that model, we add a banking sector and a monetary authority setting interest rates and credit lending conditions. The model combines Keynesian mechanisms of demand generation, a "Schumpeterian" innovation-fueled process of growth and Minskian credit dynamics. The robustness of the model is checked against its capability to jointly account for a large set of empirical regularities both at the micro level and at the macro one. The model is able to catch salient features underlying the current as well as previous recessions, the impact of financial factors and the role in them of income distribution. We find that different income distribution regimes heavily affect macroeconomic performance: more unequal economies are exposed to more severe business cycles fluctuations, higher unemployment rates, and higher probability of crises. On the policy side, fiscal policies do not only dampen business cycles, reduce unemployment and the likelihood of experiencing a huge crisis. In some circumstances they also affect positively long-term growth. Further, the more income distribution is skewed toward profits, the greater the effects of fiscal policies. About monetary policy, we find a strong non-linearity in the way interest rates affect macroeconomic dynamics: in one "regime" with low rates, changes in interest rates are ineffective up to a threshold beyond which increasing the interest rate implies smaller output growth rates and larger output volatility, unemployment and likelihood of crises.agent-based Keynesian models, multiple equilibria, fiscal and monetary policies, income distribution, transmission mechanisms, credit constraints