Marion Brouard – PhD student in economics at CREST, GENES, IP Paris

In September 2025, Marion will join Ifo/LMU Munich as an Assistant Professor.

Her research focuses on public economics and labor economics, with a focus on social insurance programs and labor market inequalities.

Her thesis, “Welfare effects of increasing transfers to young adults: Theory and Evidence”, was supervised by the economists Pierre Boyer and Camille Landais.

1. Within the laboratory, did you benefit from a working environment favorable to the advancement of your research (seminars, working groups, collective research activities)?

For me, CREST has been a wonderful working environment. The research culture there is both very open and caring. There is a lot of exchange and mutual support among PhD students, which creates a real collective dynamic. Professors are also very available and attentive to PhD students. This environment has been for me a constant source of stimulation, with particularly inspiring colleagues. Beyond scientific quality, it is above all the human qualities of the members of the department that made the progress of my thesis more pleasant and serene.

2. Has the subject of your thesis or the orientations of your research evolved since the beginning of your PhD?

When I started my thesis, I thought I would work from beginning to end on a single subject, the one I had proposed when applying. I wanted to focus on young adults, and reflect on fairer social policies capable of reducing inequalities and lowering their poverty rate, which is very high today. This theme has indeed remained at the heart of my thesis. But over time, my perspective broadened, and I gradually became interested in topics that I would not have spontaneously explored at the start, notably those inherent to the labor market. What I appreciated in the framework of the thesis is precisely this freedom: the freedom to explore, to test, to deviate a little, to ultimately better understand what really interests me.

3. Did the PhD confirm or change your initial professional project?

The PhD really transformed my professional project. When I started my thesis, I knew little about the academic world, but I was convinced that I did not want to make a career there. After the thesis, I imagined myself working in public administration. But over the years of the PhD, this certainty gradually faded. I discovered that I found real pleasure in doing research. When the time came to make a choice, I was not yet entirely sure of myself. But I finally decided to embark on an academic career, contrary to what I had imagined at the start.

4. What advice would you give to a PhD student at the beginning of the journey?

Each thesis is different, and everyone experiences it in their own way, depending on their personality, desires, and doubts. But if there is one fairly general piece of advice I could give to someone starting out, it would be to be curious, and to take full advantage of these years to learn as much as possible. Sometimes we feel like we don’t have the time to take courses, attend seminars, or read outside our subject. Yet that time is really important, it nourishes reflection and broadens perspectives — I think it is really necessary to allow oneself that.

I would also say that the PhD is made up of highs and lows. Progress in research is never linear, and that is perfectly normal. It is important to learn not to be too demanding of oneself: the periods when it feels like nothing is working are part of the process, and they in no way reflect the value or abilities of the PhD student.

5. What led you to take an interest in the question of redistribution of social assistance for young adults, and how do you explain the paradox between their high poverty rate and the low percentage of aid they receive?

Young adults are today the most financially fragile age group. Yet they are surprisingly little studied in the economic literature on social assistance. And this paradox goes further: despite their difficulties, the assistance schemes aimed at them remain very limited.

There are several possible reasons for this, but for now, there is a lack of clear research to draw firm conclusions. One of the hypotheses that I find interesting to explore is that there exists a form of ideological bias: policymakers often consider that it is up to parents to support their children, and not the State. But this view has a perverse effect, as it deepens inequalities depending on family resources. And this is clearly visible today in France, where social mobility is among the lowest of developed countries.

6. Your study uses an approach based on “social marginal utility” (SMU). Could you explain this concept? What types of data did you use to estimate social preferences and consumption behaviors?

The objective of this work is to compare the costs and benefits of an increase in social assistance for young adults. In economics, we often speak of “social marginal utility” to designate the social benefits of a policy. Concretely, this corresponds to the individual gain that a beneficiary draws from aid, weighted by the importance that society gives to this gain. For example, if society gives more weight to the well-being of the elderly than to that of young adults, then, for equal individual gains, the social benefit will be higher for the former than for the latter.

To estimate these “social weights,” I carried out a specific survey, since this type of data does not exist in classical sources. As for the individual benefits, I measure them using a well-established approach in economics: I analyze variations in consumption following changes in social assistance. Economic theory shows that the way individuals adjust their consumption in response to a financial shock reflects variations in their level of well-being. Consumption adjustments in response to a financial shock thus make it possible to estimate individual gains. For this, I use very fine data from anonymized banking transactions, which provide a precise measure of the real consumption of young adults.

7. Your results suggest that targeting low-income students would increase the relative effect on well-being eightfold. What changes would this imply in current public policies in terms of redistribution of resources?

Today, the main tool of redistribution for students is scholarships. But these scholarships remain too low: they neither compensate for inequalities linked to parental income nor guarantee decent living conditions for the most precarious students. This is very concrete: even today, one third of young people who stop their studies declare having done so for financial reasons.

Faced with this finding, a first measure would be to increase the amount of scholarships. This reform would have a relatively low cost for the State, as it is in fact a profitable investment. By making it easier to pursue studies, more young people can access better-paid jobs, which, in the long term, increases tax revenues. And above all, the social benefits are clear and very high. This measure would help reduce social inequalities and poverty among scholarship holders, who remain one of the most precarious categories today.

8. How could public policies build on your results to better orient social assistance?

I think my work mainly invites policymakers to profoundly rethink social assistance intended for young adults. What I try to show is that an increase in social transfers for young people would have very strong positive effects.

I also look at a concern often expressed by policymakers: that the State would substitute for the role of financial support from parents. It is a legitimate question, but the data show that this “substitution” mechanism actually remains limited, and above all, that this concern should not be a barrier to the implementation of more generous social policies.