Econometricians Have Their Moments: GMM at 32

The 2013 Nobel Prize for Economics was awarded to Eugene Fama, Lars Hansen and Robert Shiller for their work on empirical asset pricing. Hansen's primary contribution to the cited work was the development of the generalised method of moments (GMM), a statistical method that has proved such a valuable tool for testing the validity of empirical asset pricing models. The public announcement of the award also acknowledges the wider impact of GMM on empirical analysis in economics and beyond, referring to the 1982 Econometrica paper in which Hansen introduced the method as ‘one of the most influential in econometrics’. In this paper, we reflect on how the GMM‐based inference framework has evolved since 1982, reviewing developments on four main issues: model diagnostic testing, moment selection, identification and inference in misspecified models. We also illustrate the broader influence of GMM on econometrics by briefly exploring the connections between GMM and three other estimation methods: indirect inference, moment inequality based techniques, and a group of techniques that can be presented equivalently within either the generalised empirical likelihood or info‐metric frameworks.     

The empire strikes back: Adam Smith,John Stuart Mill,and the Robust Political Economy of empire

Recent scholarship regarding the idea of a U.S. Empire has raised serious questions as to the feasibility and desirability of imperial ambitions. This paper traces the debate over the net-benefit of empire back to the Classical economists. Adam Smith argued that the British Empire was a net cost while John Stuart Mill concluded the same empire was a net benefit. Contemporary arguments about a U.S. Empire map neatly to the divergent views of Smith and Mill. In addition to engaging in an exercise in history of thought, we use Smith’s political economy as a means of adjudicating between the different claims regarding the feasibility of empire. In doing so, we subject the claims of proponents of American Empire against the standard of robust political economy, which holds that intervention must generate desirable outcomes where less than ideal incentive and epistemic conditions hold. In doing so, we conclude that many of the claims made by proponents are fragile under less than ideal conditions.     

The collateral channel: Evidence on leverage and asset tangibility

We examine how asset structure is related to leverage in different institutional environments, using tens of thousands of firm-level observations from small, privately held, emerging market firms that are likely to face financing constraints. Our empirical analysis indicates that the linkage between asset tangibility (fixed assets as a portion of total assets) and leverage (measured as long-term debt over total assets) varies, such that in countries with fewer restrictions on collateral (land transferability), the relationship between these variables is much tighter. This also applies to the linkage between tangibility and debt maturity structure (measured as long-term debt over total debt). We find no evidence that industry concentration in different countries or changing composition of firms over time is driving our findings. The results are robust to using firm-level fixed effects specifications, to clustering error terms at the country level, and to using an alternative proxy for collateral law regime.     

A study of communication behaviour in an R & D laboratory

There is still much uncertainty about the determinants of technical communication flow in UK R & D laboratories and even more uncertainty about the causal link between communication behaviour and performance. Hence it is not clear what managerial action should be taken to improve technical communication flow and what effect such action would have on research productivity. In this study the main factors influencing communication flow are identified and the role of basic human characteristics in determining both communication behaviour and performance are studied and discussed.     

Nature Tourism Seminar

On the 10th and 11th November 1992, a two-day seminar on nature tourism was held at the Whitianga campus of the Bay of Plenty Polytechnic in New Zealand. The seminar attracted over 80 people from the northern half of New Zealand and included tourism operators, local government representatives, academics and interested members of the local community. Dr C. Michael Hall describes the objectives of this regional forum as well as the lessons learnt.