On the topology of cryptocurrency markets

Cryptocurrency markets are characterised by high volatility, high returns and comparative immaturity relative to equity and commodity markets. Topological Data Analysis (TDA) persistence norms are effective tools for the analysis of noisy dynamical systems like the cryptocurrency markets. We show how information from the shape of daily return data adds additional inference on activity within the cryptocurrency markets. TDA persistence norms embed volatility and connectedness between coins as well as incorporating information from uncertainty indexes, financial market performance and commodity returns. Our TDA measures are robust to noise and are consistent across a raft of alternative coin selections. Further, we exposit how persistence norms peak to forewarn of crashes and stay low as markets face exogenous shocks. We demonstrate the clear advantages of TDA for the study of cryptocurrency markets and develop the next steps for exploiting the potential of TDA for application to cryptocurrency markets.     

Testing for Persistence of Profits’ Differences Across Firms

We review the logic and implications underlying both static and dynamic models of competition, and associated tests of competitive effectiveness. Complications arising due to innovation, mergers and cyclical factors are discussed. Points raised in the theoretical discussion are illustrated with case histories and estimates for a number of US and UK companies. The empirical analysis tests a larger set of models than has been used in most previous work, and uses longer time series of company profits. We conclude that the patterns of profits observed in both countries are consistent with a larger and more complicated set of models of the competitive process than has been assumed until now, and that further work remains to be done in clarifying both why some firms are persistently profitable, and the nature of the ‘shocks’ that appear to produce structural breaks in the time series of companies’ profits.     

R&D and performance persistence: Evidence from the United Kingdom

There is compelling evidence from both the United States and United Kingdom suggesting that R&D investment is positively related to operating and/or market performance. This study extends prior research on R&D and valuation by further examining the sustainability or persistence of operating growth and market performance as a result of R&D investments.We use a large dataset of U.K. companies during the period 1990–2003 and our findings confirm the relation between R&D intensity and consistent growth in Sales and Gross Income, but only in the cases when a firm needs to engage in R&D activity because of the industry in which it operates. Moreover, our evidence indicates not only a positive relation between R&D intensity and subsequent risk-adjusted excess returns among firms that engage in R&D as testified by prior literature, but we also show that R&D intensity improves persistence in excess stock returns: the highest R&D-intensity firms are found to earn higher risk-adjusted excess returns more consistently than the sample median return, compared to lower R&D-intensity firms, as well as firms with no R&D. We interpret this finding as consistent with at least some form of market mispricing.     

Persistence of innovative activities, sectoral patterns of innovation and international technological specialization

In this paper, we focus on the role of persistence and heterogeneity of innovative activities at the level of the firm in determining the patterns of technological change in different industries and countries. We ask: are persistence and heterogeneity associated with higher degrees of concentration in innovative activities, stability in the ranking of innovators, and lower degrees of entry and exit in the population of innovators? Or, do the patterns of innovation depend on other variables like firm size and industrial concentration? Moreover, what are the relationships between the patterns of innovative activities, their determinants, and the technological specialization of countries? We compute indicators of persistence and heterogeneity using the OTAF-SPRU patent database at the firm level for five European countries over the period 1969–1986 for 33 technological classes. Then, we estimate the relationships between our indicators of the sectoral patterns of innovative activities and international technological specialization on the one hand, and our indicators of persistence, heterogeneity and market structure on the other. Results show that persistence and asymmetries are important (and strongly related) phenomena that affect the patterns of innovative activities across countries and sectors, while the role of market structure variables is less clear. Finally, international technological specialization is associated to a competitive core of persistent innovators.     

基于波动性-持续性的中国核心CPI测算及其评估

研究目标：基于波动性-持续性的核心通货膨胀测度方法是否适用于中国核心CPI的构建。研究方法：使用中国2001年1月至2015年12月的CPI相关数据,利用基于波动性-持续性的方法测算中国核心CPI,并与其他方法构建的核心CPI进行比较。研究发现：基于波动性-持续性的三重加权法（包括V-P-E法和T-RMSE法）构建的核心CPI是无偏的;三重加权法具有较强的追踪趋势通货膨胀的能力;在预测未来通货膨胀的能力方面,三重加权法具有较好的表现。总体来看,三重加权法是测算中国核心CPI的优良方法。研究创新：使用同时考虑波动性和持续性的方法构建中国核心CPI,并验证了其优良性。研究价值：基于三重加权法的核心CPI可作为测度中国核心通货膨胀的重要参考指标。     

Exploring international differences in inflation dynamics

Standard closed-economy DSGE models have difficulty replicating the persistence of inflation. We use a multicountry dataset to establish some empirical regularities on persistence and volatility of aggregate consumer prices for 135 countries since 1993. We find both persistence and volatility to be low (high) in developed (developing) countries relative to the full sample average. This pattern is also observed in low (high) inflation countries. We then employ a two-country DSGE framework to investigate the extent to which structural open economy features, such as incomplete exchange rate pass-through, the existence of nontraded goods, and international financial market incompleteness, can help in replicating the persistence and volatility of consumer prices. Our simulation results indicate that the model can replicate the degree of inflation persistence seen in the data for both developed and developing countries, but cannot generate the low levels of volatility observed in developed economies.     

ELUSIVE PERSISTENCE: WAGE AND PRICE RIGIDITIES,THE NEW KEYNESIAN PHILLIPS CURVE AND INFLATION DYNAMICS

Abstract We review the main New Keynesian inflation equations that have arisen as a result of aggregation from individual firms' price rigidities. We find that, on the whole, they cannot account for inflation persistence, a key feature of the empirical dynamics of inflation, and with important policy implications. The only exceptions seem to be when indexation is allowed in price setting or when price stickiness is combined with wage rigidity and staggering.     

The effects of trading activity on market volatility

The paper re-examines the question of excessive implied persistence of volatility estimates when GARCH type models are used. Ten actively traded US stocks are considered and as already established in the literature, when volume traded is inserted in the GARCH (1, 1) or (EGARCH 1, 1) models for returns, the estimated persistence is decreased. Since volume is affected also by within-the-day price movements and hence is not weakly exogenous relative to returns, alternative proxies for trading activities are suggested. It is concluded that the difference between the opening price and the closing price of the previous day accounts also for most of the persistence in the autoregressive conditional heteroskedasticity.     

Dynamics of Firm Profitability and Growth: Do Knowledge-Intensive (Business) Services Persistently Outperform?

This paper explores the persistence of profitability and growth for firms operating in the Greek service sector, paying special attention to knowledge-intensive services (KIS) and knowledge-intensive business services (KIBS). The generalized method of moments is used on a rich panel of firms over a recent nine-year period. Quantile regressions are complementarily applied for KIS and KIBS industries. The key results from both growth and profit dynamics suggest that firms in KIS and KIBS industries persistently outperform firms in less knowledge-intensive service industries, pointing to strategic advantages of the former. Importantly, KIS and KIBS seem to be able to sustain their growth and profitability persistent trends even in times of crisis. Further insight into these issues is provided by the quantile analysis, the exploration of the profitability and growth inter-linkages, and the investigation of differences among various size groups in KIS and KIBS.     

Razing San Francisco: The 1906 disaster as a natural experiment in urban redevelopment

Urban developers face frictions in the process of redeveloping land, the timing of which depends on many economic factors. This timing can be disrupted by a large shock that destroys thousands of buildings, which could then have substantial short-run and long-run effects. Studying the impact of an urban disaster, therefore, can provide unique insight into urban dynamics. Exploiting the 1906 San Francisco Fire as an exogenous reduction in the city’s building stock, this paper examines residential density across razed and unburned areas between 1900 and 2011. In prominent residential neighborhoods, density increased at least 60 percent in razed areas relative to unburned areas by 1914, and a large density differential still exists today. These outcomes suggest that thriving cities face substantial redevelopment frictions in the form of durable buildings and that large shocks can greatly alter the evolution of urban land-use outcomes over time.