Boundedness and nonlinearities in public debt dynamics: A TAR assessment

This study aims to investigate the dynamics of public debts over more than four decades for two of the main developed countries: the USA and the UK. To do this, we apply nonlinearity tests and threshold models. While the first tests enable us to check for further changes in the data, threshold models are required to assess the switching-regime hypothesis and to apprehend the main changes in public debts through different regimes. Our results provide several interesting findings. First, for both countries, we noted several structural breaks associated with well-known economic downturns, oil shocks, debt crises and financial crashes. Second, public debt dynamics seem to be characterized by various threshold effects that can improve the modeling and forecasting of public debt evolution. It is important to note that public debts vary significantly according to the regime and that a regime can be induced by specific macroeconomic factors. Keeping a close eye on such factors may help economists and policymakers to better control future public debt evolutions.     

Higher order game dynamics

Continuous-time game dynamics are typically first order systems where payoffs determine the growth rate of the players? strategy shares. In this paper, we investigate what happens beyond first order by viewing payoffs as higher order forces of change, specifying e.g. the acceleration of the players? evolution instead of its velocity (a viewpoint which emerges naturally when it comes to aggregating empirical data of past instances of play). To that end, we derive a wide class of higher order game dynamics, generalizing first order imitative dynamics, and, in particular, the replicator dynamics. We show that strictly dominated strategies become extinct in n-th order payoff-monotonic dynamics n   orders as fast as in the corresponding first order dynamics; furthermore, in stark contrast to first order, weakly dominated strategies also become extinct for n?2$n?2$. All in all, higher order payoff-monotonic dynamics lead to the elimination of weakly dominated strategies, followed by the iterated deletion of strictly dominated strategies, thus providing a dynamic justification of the well-known epistemic rationalizability process of Dekel and Fudenberg [7]. Finally, we also establish a higher order analogue of the folk theorem of evolutionary game theory, and we show that convergence to strict equilibria in n-th order dynamics is n orders as fast as in first order.     

The instability principle revisited: an essay in Harrodian dynamics

Abstract

Harrod's contribution to economic dynamics is very often reduced to the dynamic equation whose character is unstable. Growth theory and cycle theory based on Harrod's contributions aimed at reducing this instability. Following Harrod, who was strongly opposed to the ‘knife-edge’ interpretation, we define the warranted rate of growth as a ‘moving equilibrium’ and focus on its interaction with the effective rate of growth. Our simple Harrodian model generates various dynamics from stable path, to growth cycle and corridor of stability.     

Regional economic growth disparities: A political economy perspective

Regional differences in economic growth have been observed within many countries. Our story emphasises three region-specific factors driving growth—capital, labour and political factors. Conditional on differences in production factor (i.e., labour and capital) variations across democratic states, what role do differences in underlying “political factors” across regions play in accounting for regional growth disparities? We build a political economy model of endogenous growth where regions have the same political institutions, but experience different (and estimable) distributions over voter political biases (i.e., our “political factors”). In our model, political factors affect regional productivity as a consequence of politico-economic equilibrium. We discipline our regional growth accounting exercises by calibrating/estimating each model to American state-level economic and political-survey data. We show that the capital factor is the predominant driving force behind growth in American states. Nevertheless, regional variations in distributions of voter's political biases also account a great deal for regional growth disparities. We also evaluate how much politics would have distorted agents' welfare and regional growth, were regional economies given the opportunity to live under an efficient social planner's allocation system; and, if agents were to live under the same democratic system but where all voters have equal voting influence.     

Symbolic time series analysis and dynamic regimes

The mathematical theory of symbolic trajectories, whose use in multi-regime dynamics we are exploring, has also generated a set of qualitative methods of symbolic time series analysis (STSA), to be reviewed hereafter. They are illustrated by instances of multi-regime dynamics characterized by a progressively broadening regime menu, offering thus the possibility of increasingly rich regime-histories. Information-theoretic measures of complexity in dynamics are introduced, allowing for instance for cross-country or cross-sector comparisons as well as for a qualitative appraisal of structural change. The key application is to the six-regime dynamics in the Framework Space of the Italian macro-regions, whose sectorally disaggregated growth performances are taken to reflect differentiated patterns of structural change induced by capital accumulation and innovation.     

The Italian contribution to early economic dynamics

Abstract

Contrary to the prevailing literature, the study of economic dynamics began at the end of the nineteenth century, at least four decades before Hayek's and Samuelson's essays on dynamic equilibrium, as Pareto's dynamic insights prove. Throughout this early phase of the discipline, economists interested in dynamic studies put forward a wide spectrum of suggestions. This paper investigates the lines of research that sprang from the Italian debate either according to or in opposition to the Paretian mechanistic legacy, aiming to show that a growing awareness of subjective variables’ role weakened the mechanistic faith of the strictly Paretian followers, pushing them toward probabilistic analysis, anchoring dynamics to uncertainty and disequilibrium.     

The dynamics of the Jones R & D growth model

The dynamics of most prominent endogenous growth models are well understood. One notable exception is the Jones R & D growth model [Jones, C.I., 1995. R & D based models of economic growth. Journal of Political Economy 103, 759–784]. This paper provides an analytical treatment of this model's transitional dynamics. It is shown that, given constant returns to labor in R & D (as conventionally assumed in R & D growth models), a unique trajectory converging to the balanced growth path exists. The equilibrium growth path can be monotonic or oscillatory. Moreover, applying a theorem from [Arnold, L.G., 2005. The dynamics of multi-country R & D growth models. University of Regensburg Discussion Papers in Economics, No. 404. February], this result can be used to characterize the dynamic behavior of the multi-country open-economy version of the model.     

On the regime-switching and asymmetric dynamics of economic growth in the OECD countries

This study estimates the SETAR and STAR models and examines the regime-switching and asymmetric dynamics of economic growth for a comprehensive set of 10 OECD countries. The SETAR models of both Tsay and Hansen consistently reject the null hypothesis of linearity against the alternative hypothesis of threshold nonlinearity for all the sample countries. The STAR model reinforces the evidence and rejects the null hypothesis of linearity against STAR nonlinearity for all the sample countries, except Italy. The sequential F tests for the nested nulls suggest LSTAR nonlinearity for Austria, Japan, Korea, Mexico, Netherlands and New Zealand, and ESTAR nonlinearity for Finland, Germany and Norway. The forecast evaluations suggest that the SETAR models of Tsay and Hansen perform better, as compared to the AR, ARMA and STAR models. The forecasting performance of the STAR model is approximately similar to the forecasting performance of the linear AR and ARMA rivals. The persistence of lower regimes (with negative-growth or moderate-expansions) necessitates the need for the adoption of expansionary economic policies. While the longer durations of upper regimes (with positive-growth or fast-expansions) support the sustainability of the expansionary economic policies, the adequate precautions need to be taken for the inflationary implications of these policies.     

Credit constraints,growth and inequality dynamics

This paper examines how credit constraints affect the dynamics of wealth and thereby the dynamics of capital and output growth. We develop standard Ak growth models that display transitional dynamics, contrary to general belief, once the complete credit markets assumption is relaxed. The mechanism is that credit constraints make individual productivity differences persist, which in turn leads to the persistence of income inequality. The dynamics of inequality is jointly determined with the dynamics of aggregate capital. The economy thus passes through a transitional period of inequality, individual and aggregate capital dynamics before it converges to a long-run balanced growth path. The application of the model to the analysis of intergenerational mobility and inequality dynamics suggests substantial economic and policy significance. In particular, introducing credit constraints to the Barro Ak model, public investment could have an indirect impact on growth via its effect on inequality and mobility.     

Exploratory analysis of the impact of information dynamics on innovation diffusion

Understanding the dynamic nature of innovation diffusion processes, and mechanisms underlying these dynamics is crucial, since such an understanding is potentially very important in designing effective innovation support policies and developing better diffusion forecasts. The role of information diffusion in conditioning the diffusion dynamics of an innovation is the locus of this study. In order to investigate this, a simulation model that distinguishes between the real attributes of the innovation and their perceived levels by the user groups has been developed. The model makes it possible to separately trace the diffusion dynamics of innovation and the information about an innovation. Additionally, the formulation of the model enables the message broadcasted via word-of-mouth to change in nature from positive to negative, or vice versa. This generic model is used in an exploratory way, which is discussed as a novel approach for conducting a simulation-based analysis. Such an exploration covers a wide range of plausible diffusion behaviors, and aims to demonstrate the extent to which information imperfections and dynamics may influence the diffusion process. During experiments it is observed that information imperfections as well as the pace of learning processes may yield significant changes in the diffusion patterns. These changes may be in the form of altering the basic characteristics of the well-known S-shaped diffusion curve, as well as stopping the diffusion at much lower levels than full adoption. The analysis presented in the article shows that exploratory analysis is a promising way to utilize simulation models for developing general insights about dynamics processes.     

Excess payoff dynamics and other well-behaved evolutionary dynamics

We consider a model of evolution in games in which agents occasionally receive opportunities to switch strategies, choosing between them using a probabilistic rule. Both the rate at which revision opportunities arrive and the probabilities with which each strategy is chosen are functions of current normalized payoffs. We call the aggregate dynamics induced by this model excess payoff dynamics. We show that every excess payoff dynamic is well-behaved: regardless of the underlying game, each excess payoff dynamic admits unique solution trajectories that vary continuously with the initial state, identifies rest points with Nash equilibria, and respects a basic payoff monotonicity property. We show how excess payoff dynamics can be used to construct well-behaved modifications of imitative dynamics, and relate them to two other well-behaved dynamics based on projections.     

Long run time series tests of constant steady-state growth

We propose a new methodology to study the stability of steady-state growth. Long-run GDP per capita can be characterized by: (1) the linear trend hypothesis, where there are no long-run changes in GDP levels or growth rates, (2) the level shift hypothesis, where there are long-run level shifts, but not changes in growth rates, and (3) the growth shift hypothesis, where there are long-run changes in both GDP levels and growth rates. We formally test these hypotheses using time series techniques with over 139 years of data. The results are not favorable to the hypothesis of constant steady-state growth. While we find evidence supporting the linear trend hypothesis for the United States and Canada and the level shift hypothesis for three additional OECD countries, the growth shift hypothesis is supported for seven OECD and four Asian countries. The results are not driven by transition dynamics.     

Improving forecast accuracy of financial vulnerability: PLS factor model approach

We present a factor augmented forecasting model for assessing the financial vulnerability in Korea. Dynamic factor models often extract latent common factors from a large panel of time series data via the method of the principal components (PC). Instead, we employ the partial least squares (PLS) method that estimates target specific common factors, utilizing covariances between predictors and the target variable. Applying PLS to 198 monthly frequency macroeconomic time series variables and the Bank of Korea's Financial Stress Index (KFSTI), our PLS factor augmented forecasting models consistently outperformed the random walk benchmark model in out-of-sample prediction exercises in all forecast horizons we considered. Our models also outperformed the autoregressive benchmark model in short-term forecast horizons. We expect our models would provide useful early warning signs of the emergence of systemic risks in Korea's financial markets.     

Empirics of hills,plateaus, mountains and plains: A Markov-switching approach to growth

Most economic growth research has been aimed at explaining cross-country differences in average growth rates. However, it is well known that growth experiences differ over time within a country almost as much as they differ among countries. This paper builds on Pritchett's (2000) [Pritchett, Lant, Understanding patterns of economic growth: searching for hills among plateaus, mountains, and plains, World Bank Economic Review, May 2000, 14 (2), 221–250.] observation that the growth process can be thought of as transitions between different growth regimes and proposes a framework for systematic analysis of such regimes and the dynamics of the transitions. I estimate a Markov-switching regression to characterize four distinct growth regimes and transitions between them. The results show that countries switch among regimes of stable growth, “miracle” catch-up, stagnation and crisis with the transition probabilities determined by the quality of institutions. Better institutions appear to improve long-run growth by making episodes of fast growth more persistent. Low average growth rates in countries with weak institutions are a result of these countries spending more time in stagnation regimes rather then being incapable of fast growth at all. Weak institutions do not rule out growth takeoffs but limit their sustainability. The approach directs attention to shifts in growth performance and highlights the fact that identical average growth rates can mask very distinct growth paths.     

Idiosyncratic risk and aggregate employment dynamics

This paper studies how idiosyncratic productivity risk impacts aggregate employment dynamics when there is a trade-off between workers' productivity and costs of job creation and destruction. In our analysis, increasing idiosyncratic risk induces a producer to move workers out of structured jobs that are costly to create and destroy and towards less productive but more flexible unstructured positions. This substitution leaves the producer's total employment more responsive to both idiosyncratic and aggregate disturbances. If all of an industry's producers respond to heightened idiosyncratic risk in this way, then industry-wide employment can respond more to a given aggregate shock. We apply this insight to connect differences between young and old manufacturing plants' aggregate employment dynamics with their corresponding differences in idiosyncratic variability.     

Credible communication in dynastic government

This paper studies information disclosure in a model of dynastic government. When information about past policy choices comes exclusively from the reports of previous administrations, each administration has an incentive to choose its (suboptimal) one-shot expenditure policy, and then misrepresent its choice to its successor. Consequently, it has been suggested that “horizontal accountability,” i.e., a system of governance where auditing functions lie outside the executive branch, can ensure credible disclosure of a government's activities. This paper suggests a cautious approach to that view.The baseline model examines the reporting incentives of an external auditor who can independently verify the information each period. Even with auditing, credible disclosure is shown to be problematic. Various extensions to this baseline model are examined. In one extension, “liberal” (i.e., those prefering larger government expenditures) and “conservative” (those prefering smaller expenditures) regimes and auditors evolve over time. It is shown that “conservative” (“liberal”) auditors are not credible when the current regime is also “conservative” (“liberal”). Moreover, because information transmission stops when the auditor's and the regime's biases coincide, effective deterrents even in the “good” periods (when the auditor's and the administration's biases differ) are difficult to construct. In all periods the equilibrium requirement of auditor neutrality constrains the dynamic incentives for efficient policy choices. These constraints are shown to bind away from optimal policies in standard constructions of equilibrium. Various ways in which auditing protocols can overcome these problems are discussed.     

Lange's 1938 model: dynamics and the “optimum propensity to consume”

Abstract

Oskar Lange's 1938 article “The Rate of Interest and the Optimum Propensity to Consume” is usually associated with the original IS-LM approach of the late 1930s. However, Lange's article was not only an attempt to illuminate Keynes's main innovations but the first part of a wide project that included the development of a theory of economic evolution. This paper aims at showing that Lange's article can help in illuminating critical aspects of this project: in particular, Lange's idea that a synthesis between Kaldor's and Kalecki's theories and that of Schumpeter, might have been possible and that it represented (in intentions) a “modern” and consistent reconstruction of the Marxist theory of the business cycle. Section 2 clarifies Lange's early reflection on dynamics. Section 3 centres on Lange's 1938 static model and indicates the effects of a change of saving on investment. Section 4 suggests a dynamic reconstruction from which are addressed important arguments raised by Lange in a series of papers written between 1934 and 1942.     

Solow's Harrod: Transforming macroeconomic dynamics into a model of long-run growth

Modern growth theory derives mostly from Solow's “A Contribution to the Theory of Economic Growth” (1956). Solow's own interpretation locates its origins in his view that Harrod's growth model implied a tendency toward progressive collapse of the economy. He formulates his view in terms of Harrod's invoking a fixed-coefficients production function. We challenge Solow's reading of Harrod's “Essay in Dynamic Theory,” arguing that Harrod's object in providing a “dynamic” theory had little to do with the problem of long-run growth as Solow understood it, but instead addressed medium-run fluctuations, the “inherent instability” of economies. Solow's interpretation of Harrod was grounded in a particular culture of understanding embedded in the practice of formal modelling that emerged in economics in the post-Second World War period. Solow's interpretation, which ultimately dominated the profession's view of Harrod, is a case study in the difficulties in communicating across distinct interpretive communities and of the potential for losing content and insights in the process. Harrod's objects – particularly, of trying to account for a tendency of the economy toward chronic recessions – were lost to the mainstream literature.     

The impact of productivity and demand shocks on structural dynamics: Evidence from Austrian manufacturing

Based on Pasinetti's model of structural dynamics we develop an empirical identification strategy for aggregate and sectoral labor productivity and demand shocks in a structural vector autoregressive model with long-run restrictions. Impulse response analysis shows that we can distinguish four patterns of the effects of changes in demand and productivity growth on sectoral output growth. For some industries demand is indeed the factor driving sectoral growth. Labor productivity and demand shocks are closely associated with the growth rates of employment and output across industries. However, there is less correlation with entry and exit. This suggest that structural change within and between industries may have quite different determinants.