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This article investigates the robustness of impulse response estimators to near unit roots and near cointegration in vector autoregressive (VAR) models. We compare estimators based on VAR specifications determined by pretests for unit roots and cointegration as well as unrestricted VAR specifications in levels. Our main finding is that the impulse response estimators obtained from the levels specification tend to be most robust when the magnitude of the roots is not known. The pretest specification works well only when the restrictions imposed by the model are satisfied. Its performance deteriorates even for small deviations from the exact unit root for one or more model variables. We illustrate the practical relevance of our results through simulation examples and an empirical application.

The purpose of this paper is to examine the time series behavior of Greek labor market series by providing an empirical perspective on trend breaks and unit roots. Trend breaks represent aggregate behavior responses to “infrequent” changes in economic fundamentals, including changes in fiscal or labor market conditions, as have been perceived in Greece during the last years. Unit roots reveal whether “regular” shocks have significant effects on the level of the series over a specified finite horizon.

The authors employ recent procedures that deal with the “circular testing problem” between tests on the parameters of the trend function and unit root tests that often arises in empirical applications. These techniques assess trend function stability and are robust regardless of whether the noise component is stationary or having a unit root. Then, conditional on the presence of breaks, the authors test whether the series can be characterized by a stochastic trend.

The analysis provides evidence of “infrequent” trend breaks that appear to coincide with the recent global economic crisis and the implementation of the counteraction (fiscal) measures to the Greek debt crisis. Allowing for trend breaks does not lead to a rejection of the unit root hypothesis, which might reflect the low flexibility of the country’s labor market operation.

The procedures employed can be viewed as new tools that might help empirical researchers to explore more accurately the characteristics of individual time series and to find reasonable approximations to the true processes of the time series examined.

The paper provides new information on the presence of structural changes in the Greek labor market, and on whether the “aggressive” and “occasional” nature of fiscal measures can be approximated by infrequent changes in the slope of the trend function.

This paper provides a selective survey of the panel macroeconometric techniques that focus on controlling the impact of “unobserved heterogeneity” across individuals and over time to obtain valid inference for “structures” that are common across individuals and over time. We consider issues of (i) estimating vector autoregressive models; (ii) testing of unit root or cointegration; (iii) statistical inference for dynamic simultaneous equations models; (iv) policy evaluation; and (v) aggregation and prediction.

The purpose of this paper is to examine the validity of the purchasing power parity (PPP) hypothesis for two Southern African countries, namely: Lesotho and Zambia.

The authors utilized four econometric tests to examine the existence of the PPP hypothesis in Lesotho and Zambia. These tests include two unit root tests without structural breaks – the Dickey-Fuller generalized least squares (DF-GLS) test and the Ng-Perron test; and two unit root tests with structural breaks – the Perron test and the Zivot-Andrews test. The authors’ empirical analysis is based on an annual data set with varying time periods. The sample period spanned 1960-2010 and 1955-2010, for Lesotho and Zambia, respectively.

The authors found that the PPP hypothesis was supported in the case of Lesotho, but rejected in the case of Zambia.

This paper is the first to simultaneously explore the exchange rate policies, trends, and the PPP for these two countries. The implication of this finding is that Lesotho is unlikely to profit immensely from trade and investment arbitrages; whereas Zambia is more likely to profit immensely from trade and investment arbitrage by trading with the USA. Moreover, the authors’ findings indicate that the PPP doctrine may be a useful guide for the exchange rate and other macroeconomic adjustment policies in Lesotho but not in Zambia.

The purpose of this paper is to highlight some testing procedures, both in time/frequency framework, useful to test for significant cycles in insurance data. The US underwriting cycle is measured using the growth rates of real premiums.

In addition to the traditional AR(2) model, two new approaches are suggested: testing for a significant peak in the periodogram using Fisher g test and a nonparametric version of it, and testing for unit root cycles in insurance data.

All approaches find empirical evidence for a cyclical behaviour of the growth rates of property‐liability real premiums. Results on the length of dominant cycle still diverge, according to the approach (time/frequency domain).

Compared to the existing literature, the present study innovates in that it highlights additional testing procedures, helpful to detect significant cycles in insurance time series. The underwriting cycle is analysed through the growth rates of real premiums.

The purpose of the paper is to examine the seasonal structure in the German monetary aggregate M1 and output by means of fractional integration techniques.

The authors use a version of the tests of Robinson that permits testing seasonal I (d) models with the possibility of incorporating seasonal dummy variables and structural breaks.

The results show that there is a strong degree of persistence in their behaviour, especially at the long run or zero frequency, with orders of integration ranging between 1.25 and 1.50.

The main innovation in this work is the use of a new time series approach to the case of seasonality.

This study aims to examine the hysteresis hypothesis in unemployment using monthly data from 13 countries in transition.

Stationarity in the unemployment rate of selected transition economies was analyzed using four different group unit root tests, namely, linear, structural breaks, non-linear and structural breaks and non-linear.

The empirical results show that the unemployment hysteresis hypothesis is valid for the majority of transition economies, including Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, the Kyrgyz Republic, Latvia, Lithuania, Poland, Romania and Slovenia. However, the results strongly reject the null hypothesis of unemployment hysteresis for the Kazakhstan and the Slovak Republics.

This study revealed that, for countries in transition, advanced unit root tests exhibit greater validity when compared to standard tests

With the growth of income at the global level, the World Bank data show that there are rising levels of income disparity across countries, groups, regions and within the countries. This fact otherwise hints at the inter-country divergence in incomes, particularly between the developed and developing countries of the world. This chapter, therefore, attempts to examine the convergence or divergence in credit, GDP and HDI across the 10 selected countries for the period of 1990–2019 applying the neoclassical growth approach and the time series approach. The results of the exercise in line with the neoclassical theories on absolute convergence and sigma convergence show that the countries are unquestionably converging in GDP and HDI with mixed results in case of credit. The results of convergence in GDP and HDI in all the countries and their developed and developing counterparts provide a possible explanation as to why the cross countries’ income inequalities as well as world inequality in income and development are reducing over time. On the other hand, the results of the time series approach display that credit and HDI are converging in both absolute and conditional terms but the countries are converging in conditional terms only for GDP. Thus, the claims of the World Bank are not valid for the selected countries in the chapter, rather, they can be verified by taking other countries and groups into consideration.