The speed of biased random walk among random conductances

We consider biased random walk among iid, uniformly elliptic conductances on $\mathbb{Z}^d$, and investigate the monotonicity of the velocity as a function of the bias. It is not hard to see that if the bias is large enough, the velocity is increasing as a function of the bias. Our main result is that if the disorder is small, i.e. all the conductances are close enough to each other, the velocity is always strictly increasing as a function of the bias, see Theorem 1. A crucial ingredient of the proof is a formula for the derivative of the velocity, which can be written as a covariance, see Theorem 3: it follows along the lines of the proof of the Einstein relation in [GGN]. On the other hand, we give a counterexample showing that for iid, uniformly elliptic conductances, the velocity is not always increasing as a function of the bias. More precisely, if $d=2$ and if the conductances take the values $1$ (with probability $p$) and $\kappa$ (with probability $1-p$) and $p$ is close enough to $1$ and $\kappa$ small enough, the velocity is not increasing as a function of the bias, see Theorem 2

Paving the Roadway for Safety of Automated Vehicles: An Empirical Study on Testing Challenges

The technology in the area of automated vehicles is gaining speed and promises many advantages. However, with the recent introduction of conditionally automated driving, we have also seen accidents. Test protocols for both, conditionally automated (e.g., on highways) and automated vehicles do not exist yet and leave researchers and practitioners with different challenges. For instance, current test procedures do not suffice for fully automated vehicles, which are supposed to be completely in charge for the driving task and have no driver as a back up. This paper presents current challenges of testing the functionality and safety of automated vehicles derived from conducting focus groups and interviews with 26 participants from five countries having a background related to testing automotive safety-related topics.We provide an overview of the state-of-practice of testing active safety features as well as challenges that needs to be addressed in the future to ensure safety for automated vehicles. The major challenges identified through the interviews and focus groups, enriched by literature on this topic are related to 1) virtual testing and simulation, 2) safety, reliability, and quality, 3) sensors and sensor models, 4) required scenario complexity and amount of test cases, and 5) handover of responsibility between the driver and the vehicle.Comment: 8 page

The end of stability and growth pact?

This paper evaluates the Stability and Growth Pact. After examining the rules in place and the experience so far, the Pact is analysed from a political economy perspective, focusing on the choice for so-called soft law and drawing inferences from characteristics of successful fiscal rules at the state level in the United States. It is also examined whether big and small countries are likely to adhere to fiscal policy rules in place. Furthermore, the impact of the business cycle on fiscal policy outcomes is analysed. Finally, the proposals of the European Commission to strengthen the Pact are discussed. --stability and growth pact,EMU,budget discipline

Capital Controls and Exchange Rate Regimes: An Empirical Investigation

It is often argued that deregulation of international transactions and its effects on the “globalization” of financial markets is behind the decline in the attractiveness of fixed exchange rate regimes. We argue that, instead, much of the recently observed decrease in the level of capital controls should be seen as endogenous to the exchange rate regime decision. We find that the durability of a peg (measured on the basis of the growth of international reserves), the political benefits of a commitment to a peg, domestic and foreign inflation (aversion), as well as business cycle volatility and synchronization are the main determinants of capital controls. The empirical analysis is based on data for 53 non-OECD countries covering the period 1980-94.Monetary policy, exchange rates, capital controls

Which variables explain decisions on IMF credit? An extreme bounds analysis

This paper analyses which economic and political factors affect the chance that a country receives IMF credit or signs an agreement with the Fund. We use a panel model for 128 countries over the period 1972-1998. Our results, based on Extreme Bounds Analysis, suggest that it are mostly economic variables that are robustly related to IMF lending activity, while most political variables that have been put forward in previous studies on IMF involvement are non-significant. To the extent that political factors matter, they seem more closely related to the conclusion of IMF agreements than to the disbursement of IMF credits. --IMF credit,political economy

Which Variables Explain Decisions on IMF Credit? An Extreme Bounds Analysis

IMF credit, political economy

Does money matter in the ECB strategy? New evidence based on ECB communication

We examine the role of money in the policies of the ECB, using introductory statements of the ECB President at the monthly press conferences during 1999-2004. Over time, the relative amount of words devoted to the monetary analysis has decreased. Our analysis of indicators of the monetary policy stance suggests that developments in the monetary sector, while somewhat more important in the later half of the sample, only played a minor role most of the time. Our estimates of ECB interest rate decisions suggest that the ECBs words (monetary-sector based policy intensions) are not an important determinant of its actions. --ECB,communication,monetary policy

IMF Credit: How Important Are Political Factors? A Robustness Analysis

We test whether, in addition to economic conditions, IMF credit is influenced by political factors. On the basis of a panel model for 128 countries over the period 1972-1998, we find that debt service scaled to exports, international reserve holdings scaled to imports and economic growth, as well as investment are robustly related to IMF credit supply. Arguably, these results are broadly consistent with the IMF’s mission. The only political variables which appear to be related to changes in IMF credit are government stability, the quality of the bureaucracy, and a dummy variable indicating the extent of political opposition. Possible interpretations of these findings are discussed.IMF credit, political economy.