Why have Bordeaux wine prices become so difficult to forecast ?Journal articleStephen Bazen and Jean-Marie Cardebat, Economics Bulletin, Volume 42, Issue 1, pp. 124-142, 2022

In an earlier article, we found that a univariate state space time series model estimated using the Kalman filter provided reasonably accurate monthly forecasts of generic Bordeaux red wine prices for the period up to 2016. We use the same model to forecast prices for the period 2017 to 2020, a period in which the market for this wine was subject to a number of demand and supply shocks. We find that the model's forecasts are poor from late 2018 through 2019 when the price collapsed from an all-time high and returned levels not seen since 2012. There is evidence of a structural break or regime change, and we explore the underlying reasons for this. The main one is the collapse in Chinese demand for Bordeaux wines which was brought about by a combination of shocks.

Quelles conditions d'accès à l'emploi pour les jeunes mères isolées ?Book chapterStephen Bazen, Xavier Joutard and Hélène Périvier, In: Chemins vers l’emploi et la vie adulte : l’inégalité des possibles, Thomas Couppié, Arnaud Dupray, Céline Gasquet and Elsa Personnaz (Eds.), 2022-12, Number 4, pp. 97-105, CEREQ - Centre d'études et de recherches sur les qualifications, 2022

Si la présence d’un enfant pénalise l’accès à l’emploi des jeunes mères, la monoparentalité n’aggrave pas leur capacité d’accès à un premier emploi. En revanche, être mère isolée retarde l’accès au CDI à temps complet des femmes les moins diplômées, et donc leur insertion durable, à l’inverse des plus diplômées.

Étude sur la situation économique et sociale des parents isolés : niveau de vie, marché du travail et politiques publiquesReportHélène Périvier, Guillaume Allègre, Stephen Bazen, Bruno Ducoudre, Xavier Joutard, Pierre Madec, Muriel Pucci and Raul Sampognaro, pp. 72, 2020
The integration of young workers into the labour market in FranceJournal articleStephen Bazen and Khalid Maman Waziri, International Journal of Manpower, Volume 41, Issue 1, pp. 17-36, 2020

Using a representative survey of young persons having left full-time education in France in 1998 and interviewed in 2001 and 2005, the purpose of this paper is to examine the process of their integration into normal employment (a stable job with a standard employment contract) and the extent to which job matches are inefficient in the sense that the pay in a job is below an individual's potential earnings. The latter are determined principally by diploma level and educational specialisation, although other forms of training and labour market experience are relevant.

A stochastic earnings frontier approach is used in order to examine workers' ability to capture their full potential earnings in labour markets where there is inefficient job matching (due to the lack of information, discrimination, over-education or the process of integration).

The results suggest that young workers manage to obtain on average about 82 per cent of their potential earnings three years after leaving full-time education and earnings inefficiency had disappeared four years later. The results are robust to the treatment of selectivity arising from the exclusion of the unemployed in the estimation of the frontier.

The stochastic earnings frontier is a useful and appropriate tool for modelling the process of labour market integration of certain groups (young persons, migrants and the long-term unemployed) where over-education due to inefficient initial job matches occurs. Over time this situation tends to be rectified as job mobility leads to improved matching and less inefficiency.

Forecasting Bordeaux wine prices using state-space methodsJournal articleStephen Bazen and Jean-Marie Cardebat, Applied Economics, Volume 50, Issue 47, pp. 5110-5121, 2018

Generic Bordeaux red wine (basic claret) can be regarded as being similar to an agricultural commodity. Production volumes are substantial, they are traded at high frequency and the quality of the product is relatively homogeneous. Unlike other commodities and the top-end wines (which represent only 3% of the traded volume), there is no futures market for generic Bordeaux wine. Reliable forecasts of prices can to large extent replace this information deficiency and improve the functioning of the market. We use state-space methods with monthly data to obtain a univariate forecasting model for the average price. The estimates highlight the stochastic trend and the seasonality present in the evolution of the price over the period 1999 to 2016. The model predicts the path of wine prices out of sample reasonably well, suggesting that this approach is useful for making reasonably accurate forecasts of future price movements.

Federal minimum wage hikes do reduce teenage employment. A replication study of Bazen & Marimoutou (Oxford Bulletin of Economics and Statistics, 2002)Journal articleStephen Bazen and Vêlayoudom Marimoutou, International Journal for Re-Views in Empirical Economics (IREE), Volume 2, Issue 2018-5, pp. 1-13, 2018

In 2002 we published a paper in which we used state space time series methods to analyse the teenage employment-federal minimum wage relationship in the US (Bazen and Marimoutou, 2002). The study used quarterly data for the 46 year period running from 1954 to 1999. We detected a small, negative but statistically significant effect of the federal minimum wage on teenage employment, at a time when some studies were casting doubt on the existence of such an effect. In this note we re-estimate the original model with a further 16 years of data (up to 2015). We find that the model satisfactorily tracks the path of the teenage employment-population ratio over this 60 year period, and yields a consistently negative and statistically significant effect of minimum wages on teenage employment. The conclusion reached is the same as in the original paper, and the elasticity estimates very similar: federal minimum wage hikes lead to a reduction in teenage employment with a short run elasticity of around – 0.13. The estimated long run elasticity of between – 0.37 and – 0.47 is less stable, but is nevertheless negative and statistically significant.

Guest editorialJournal articleStephen Bazen and Jean-Marie Cardebat, International Journal of Manpower, Volume 38, Issue 1, pp. 2-3, 2017
Do earnings really decline for older workers?Journal articleKadija Charni and Stephen Bazen, International Journal of Manpower, Volume 38, Issue 1, pp. 4-24, 2017

Cross-section data suggest that the relationship between age and hourly earnings is an inverted U shape. Evidence from panel data does not necessarily confirm this finding suggesting that older workers may not experience a reduction in earnings at the end of their working life. The paper aims to discuss this issue.

In this paper the authors use panel data on males for Great Britain in order to examine why the two types of data provide conflicting conclusions. Concentrating on the over 50s, several hypotheses are examined: overlapping cohorts, job tenure, job-changing, labour supply behaviour, and selectivity bias.

Cohort and individual fixed effects partly explain the divergent conclusions. However, for fully, year-on-year employed individuals, there is no evidence of earnings decline at the end of working life. The authors find no role for selectivity due to retirement, although shorter working hours or partial retirement along with job-changing late in life does provide an explanation for why hourly earnings decline for certain older workers.

The authors find no evidence that the process of ageing itself leads to lower earnings as suggested by the cross-section profile.

An Oaxaca decomposition for nonlinear modelsJournal articleStephen Bazen, Xavier Joutard and Brice Magdalou, Journal of Economic and Social Measurement, Volume 42, Issue 2, pp. 101-121, 2017

The widely used Oaxaca decomposition applies to linear models. Extending it to commonly used nonlinear models such as duration models is not straightforward. This paper shows that the original decomposition that uses a linear model can also be obtained by an application of the mean value theorem. By extension, this basis provides a means of obtaining a decomposition formula which applies to nonlinear models which are continuous functions. The detailed decomposition of the explained component is expressed in terms of what are usually referred to as marginal effects. Explicit formulae are provided for the decomposition of some nonlinear models commonly used in applied econometrics including binary choice, duration and Box-Cox models.

Musicians and the Creative Commons: A survey of artists on JamendoJournal articleStephen Bazen, Laurence Bouvard and Jean-Benoît Zimmermann, Information Economics and Policy, Volume 32, Issue C, pp. 65-76, 2015

Piracy and the peer-to-peer diffusion of music deprive artists of income and constitute a challenge to music industry. Many consumers, especially in younger age groups, consider that is normal not to pay in order to listen to music yet artists have intellectual property rights. The reconciliation of these two features of the music market is increasingly difficult within the traditional business model of the music industry. This paper uses an original survey of artists whose music is diffused freely on the online platform Jamendo (the largest of its kind) and which uses Creative Commons (CC) licences rather than copyright firstly to examine why so many artists would adhere to such an approach and secondly what the artists feel about CC. Age is clearly a factor in the choice of CC licence type, as well as whether artists derive income from their music. The choice of CC over copyright is also found to be related to its greater flexibility, its role in the development of musical creation and its function as means of sharing. It can be seen as a basis for an alternative business model in the music industry, in which sales of albums no longer constitute the main source of artists’ remuneration.