Recent progress in econophysics： Chaos, leverage, and business cycles as revealed by agent-based modeling and human experiments

Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like ＂intelligence＂ remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents＇ intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.

The stationary solution of a random dynamical model

This paper studies the stationary probability density function（PDF） solution of a nonlinear business cycle model subjected to random shocks of Gaussian white-noise type. The PDF solution is controlled by a Fokker–Planck– Kolmogorov（FPK） equation, and we use exponential polynomial closure（EPC） method to derive an approximate solution for the FPK equation. Numerical results obtained from EPC method, better than those from Gaussian closure method, show good agreement with the probability distribution obtained with Monte Carlo simulation including the tail regions.

Business Cycle Asymmetry in China:Evidence from Friedman's Plucking Model

Friedman＇s plucking model of business fluctuations suggests that output cannot exceed an upper limit, but it is occasionally ＂plucked＂ downward below trends as a result of economic recessions. This paper investigates China＇s business fluetuations using quarterly real GDP data for the period 1978 2009. Our results show some evidence supporting Friedman＇s plucking model. We find that a ceiling effect of real output exists, and that negative asymmetric shocks significantly affect the transitory component, which captures the plucking downward behavior during the recession. The results also suggest that the basic asymmetric unobserved component model is not appropriate for directly modeling China＇s real output because the business＂ cycle is inaccurately measured, but it works quite well when considering a structural break in the second quarter of 1992. The results reveal that although China＇s economy strengthened in the second quarter of 2009, it is essential for China＇s government to take further positive and effective measures to maintain sustainable development of the economy.

Business Cycle in China since the Lehman Crisis:Interaction among Macroeconomic Policy,Economic Growth and Inflation

The major objectives of China＇s macroeconomic policy are to stabilize economic growth and inflation, which, in turn, are important factors determining key prices, such as the policy interest rate, the renminbi exchange rate and stockprices. In a framework that distinguishes different phases of the business cycle based on whether the current period＇s economic growth rate and inflation rate are above or below their ＂＇normal＂ values, this paper analyzes the interaction among macroeconomic policy, economic growth and inflation in China since the Lehman crisis, and the implications for these key prices. The path of China＇s economy indicates that stimulus measures taken by the government during the recession phase and tightening measures implemented during the overheating phase have helped minimize the fluctuation over the business cycle. Our analysis shows that Chinese authorities tend to rely more on adjusting the exchange rate than the interest rate to stabilize the economy. Comparing with conditions at the time of the post-Lehman recession, the current slowpace of economie growth in China may reflect not only weakening demand, but also a lowerpotential growth rate associated with the arrival of the Lewis turning point.

On business cycle forecasting

We develop a recession forecasting framework using a less restrictive target variable and more flexible and inclusive specification than those used in the literature.The target variable captures the occurrence of a recession within a given future period rather than at a specific future point in time(widely used in the literature).The modeling specification combines an autoregressive Logit model capturing the autocorrelation of business cycles,a dynamic factor model encompassing many economic and financial variables,and a mixed data sampling regression incorporating common factors with mixed sampling frequencies.The model gene rates significantly more accurate forecasts for U.S.recessions with smaller forecast errors and stronger early signals for the turning points of business cycles than those gene rated by existing models.

Is political business cycle an enemy to human development?Empirical evidence from Africa

Extant literature has argued that,with major extension of democracy since the 1990s,political business cycle has become more intense and has made African political systems more fragile.In light of this,this paper examines both the existence of African political business cycles and their impact on human development.It confirms the existence of political business cycles in Africa.Estimates of a panel fixed effects and system-GMM regression techniques for 38 African countries from 1990 to 2015 also suggest that such cycles worsen human development in African countries.This finding is consistent if we limit our analysis to various sub-regions of Africa,and also at two different income levels.

A new broom sweeps clean:is there a Chinese-style political business cycle?

Politics is an important cause of economic growth and fluctuations.We present a new Political Business Cycle(PBC)Theory based on the background of recent Chinese economic transformation and government behaviors,explore the economic impact of the National Congress of the Communist Party of China(CPC),the National People’s Congress(NPC)and Chinese People’s Political Consultive Conference(CPPCC)and how they shape and influence the behaviors of local government officials.Based on 1994-2012 inter-provincial panel data of China and using SYS-GMM and LSDVC,we find that there are significant effects in China of PBC and government administration change.Changes in government administration influence the economic behaviors of local governments,which in turn influence local economic development through fiscal decentralization and political promotion tournament.These effects are sustained and robust.In this paper we offer an economic explanation for the Chinese proverb“a new broom sweeps clean,”and try to verify the Chinese-style Political Business Cycle(CPBC).We provide new ideas for further improving the functions of government,optimizing macroeconomic control,and preventing personnel changes in the government from overheating the economy.

An Estimated DSGE Model for Business Cycle Analysis in China

A small-scale, but highly-stylized dynamic stochastic general equilibrium model is estimated by the maximum likelihood method using Chinese quarterly data. Model specifications and parameter equalities between various competing model variants are addressed by formal statistical hypothesis tests, while implications for business cycle fluctuations are evaluated via a variance decomposition experiment, second-moments matching, and some out-of-sample forecast exercises. It is highlighted that the monetary authority takes an aggressive stance to the current inflation pressure （there is a significant lagged response）, while leaving less attention to changes in aggregate output. Variance decomposition reveals that large percentages of variations in real and nominal variables are explained by the highly volatile preference and potential output shock, respectively. When nominal and real frictions as well as additional shocks are included, overall our estimated model can successfully reproduce the stylized facts from actual data of Chinese business cycles and frequently can even outperform those forecasts from an unconstrained VAR.