Departmental news

Dr Federico RossiLink opens in a new window, Associate Professor of Economics at the University of Warwick, is one of just 400 researchers across Europe to have been awarded an ERC Starting Grant, and the only successful applicant from the University of Warwick.

The grants are intended to support cutting-edge research in a wide range of fields, from medicine and physics to social sciences and humanities. The ERC say the funds are awarded to “help researchers at the beginning of their careers to launch their own projects, form their teams and pursue their best ideas.”

Dr Rossi has been awarded €1.45m for an ambitious five-year study, Human Capital, the Organisation of Production, and Economic Development – HUMANDEV for short.

He explains:

“The ERC grant will allow me to kick-start a new research agenda on the role of human skills for the past and the future of economic development.

“There is a general sense among economists and policy-makers that the accumulation of human capital is key ingredient of economic growth, but we don’t have yet a clear understanding of which specific skills are particularly important, why their accumulation varies so much across countries and over time, and how exactly these skills transform the process of production.

“My project, HUMANDEV, will leverage micro-level data from many countries and new theoretical frameworks to shed light on these issues.

“A key objective of this work will be to provide insights on how educational and training policies can facilitate the adaptation to some of the most pressing global challenges of our time, such as population ageing, climate change, and technological change.

“I am extremely grateful to the ERC for supporting this endeavour.”

Commenting on the awards programme as a whole, ERC President Professor Maria Leptin said:

“It is part of our mission to give early-career talent the independence to pursue ambitious curiosity-driven research that can shape our future. In this latest round of Starting Grants, we saw one of the highest shares of female grantees to date, which I hope will continue to rise. Congratulations to all winners and good luck on your path to discovery.”

This competition attracted over 2,696 proposals, which were reviewed by panels of renowned researchers from around the world. The overall success rate was 14.8%. The grants are expected to create more than 2,600 jobs for postdoctoral fellows, PhD students and other staff at the host institutions.

The European Research Council (ERC) is a public body for funding of scientific and technological research conducted within the European Union (EU).

This year’s National Student Survey (NSS) results show a continuing high level of satisfaction among Economics final year undergraduates across almost all themes in the survey.

Almost 90 per cent of Economics finalists say they would recommend Warwick to future students, 7 per cent more than the average across the university.

Other areas where finalists indicated strong satisfaction with their course include:-

• Course content: 92% of participants agreed that they had found their Economics course intellectually stimulating; while 90% agreed that the course had often challenged them to achieve their best work.
• Study resources: 91% of respondents agreed that they had been well supported with IT resources and facilities.
• Feedback and academic support: 91% of respondents agreed that they received assessment feedback on time; while 90% of finalists agreed that it was easy to contact teaching staff when they needed to.

The cohort of students taking part in this year’s NSS had arrived at Warwick under the exceptional circumstances of the COVID 19 pandemic. The Department was pleased to note that 88 per cent of the survey participants felt that information about Warwick’s mental wellbeing support services had been well-communicated.

The annual UK-wide survey gathers final year undergraduate students' opinions on the quality of their courses. The Department carefully analyses the feedback received from the NSS. Every year the quantitative scores and the comments made help shape the future of Economics in the Department and the University of Warwick.

Changes to the survey questions and the response scales make direct year-on-year comparisons not possible in 2023. The data, however, allows the Department to compare​ Economics to other courses at Warwick, and to benchmark its performance against other universities.

Detailed comparisons with other UK Economics departments will be made later this year; however, initial analysis comparing Warwick’s results to other Departments within the Russell Group of research-intensive universities, are very positive, with Warwick Economics ranking in the top 5 across two thirds of the questions.

Head of Department Ben Lockwood commented:

“As a department we strive to deliver an outstanding student experience. The feedback we receive through the NSS is one of the tools which helps us to understand and meet student needs.

“We are of course delighted to receive strong satisfaction levels in so many areas and we will look closely at the areas where, as a Department, we have done less well to see what changes may be required.

“I would like to thank all of this year’s finalists. They have certainly had a very different university experience to the norm and it is a huge credit to them that they engaged with new ways of teaching, learning and research with great resilience. The Department is absolutely delighted that 90 per cent of our finalists would recommend Warwick.

“I would also like to thank all of our staff who rose to the challenge of delivering Covid-safe teaching and learning, and those who work behind the scenes to keep everything running. These high satisfaction scores are a real tribute to your skills and commitment.”

15 August 2023

We are delighted to announce that Warwick’s Department of Economics has risen three places in the QS World University Ranking for Economics and Econometrics, from 25^th in the world to 22nd.

The QS World University Rankings are compiled annually, using research citations and the results of major global surveys of employers and academics to classify the universities in 54 different disciplines.

The 2023 rankings were published on 22 March with the welcome news that after consistently ranking at 25^th in the word for several years, the Department has improved its standing by three places.

The Department ranks in 5^th place in the UK, behind only LSE, Oxford, Cambridge and UCL; and scored more highly than Oxford and Cambridge on the “citations per paper” metric, a testament to the Department’s excellent research output.

Commenting on the news, Professor Ben Lockwood, Head of Department of Economics, said:

“It is very good news to hear that the Warwick Economics Department has improved its position in the independent QS World University Rankings.

“In this ranking, departments are scored on the issues which we know matter to prospective students – academic reputation, judged by our peers; employer reputation, based on responses from more than 75,000 graduate employers worldwide; and the quality and impact of our research.

“I would like to thank all our staff and students for their work in creating a Department whose reputation in the eyes of our academic peers and in the eyes of the employers who recruit our students is among the world’s best.

“We will continue to recruit talented and ambitious research and teaching staff at all stages of their academic careers, and highly capable students, as part of our ongoing commitment to being a world-class economics department.”

Useful links:

•  Economics ranked 25th in the QS World University Rankings 2021 (warwick.ac.uk)
• QS World University Rankings for Economics and Econometrics 2023 | Top Universities, published 2023.
• About the Department of Economics, University of Warwick
• Find out more about Our Reputation
• Learn about Our Community Values
• Study with us
• Work with us

The Department congratulates recent PhD graduate Ozge Demirci, who has won the CESifo Distinguished Affiliate Award for her research in the economics of digitisation.

 Ozge Demirci has been awarded the Distinguished CESifo Affiliate AwardLink opens in a new window in the area of the economics of digitisation by the CESifo Research Network. The award is intended for promising young economists and is granted for the best paper presented at the CESifo Area Conferences. An award committee gives the award to a young economist on the basis of the scientific originality, policy relevance, and quality of exposition in their research. 

Ozge's research is in applied microeconomics with a focus on the economics of digitisation and discrimination. Some of her recent research investigates the impacts of regulations targeting algorithmic bias. She analyzes if anti-discriminatory policies that ban using sensitive information such as race or gender in algorithmic processes are effective or whether algorithms adjust to circumvent the regulations.

In her award-winning paper "Can Gender-Blind Algorithmic Pricing Eliminate the Gender Gap?" Dr Demirci uses a natural experiment to investigate the impact of gender-blind algorithmic pricing on consumers and firms. She focuses on a recent policy regulation that prohibits using gender information in pricing algorithms for automobile insurance in the US. Her research investigates how this policy affects the insurance premiums paid by male and female consumers and the pricing algorithms companies use. 

Ozge's findings show that after the policy was implemented, algorithms started to price features correlated with the riskiest gender group, young males, significantly more. For instance, drivers using specific car models associated with young males started paying more after the ban.

Dr Demirci's findings illustrate the limitations of anti-discrimination policies that impose group-blind pricing and have implications for the design of fairer regulations for algorithms.

Dr Demirci's winning paper will appear in the CESifo Working Paper SeriesLink opens in a new window.

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Ozge Demirci is a PhD graduate in Economics at the University of Warwick. She has received several awards during her graduate studies, including Outstanding Paper Award at Discrimination and Diversity Workshop and the Emerging Scholar Award from the Diversity in Organizations, Communities, and Nations Research Network. Additionally, her research has received several grants, including a research grant from the Royal Economics Society and the Dissertation Fellowship from the University of Warwick.

Find more about Ozge's researchLink opens in a new window

In the next feature in our series focusing on our undergraduate entrepreneurs, we meet the team behind Butterfly, a new app taking flight on campus.

Alex Reid, Zain Mobarik and Josh Okusi (pictured above, left to right) are a team with an ambitious vision – they plan to “put the social back into social media” with their app, Butterfly.

Second year Economics student Alex and his friends were workshopping ideas for a new sorting algorithm Josh had developed. They realised that they had a bigger vision than simply ranking undergraduates according to their popularity – why not make an app that would help to bring digital friendships off the screen and into the real world?

Alex explains: “We all felt that social media has lost its way – far from being social, these days it is about passive scrolling and the consumption of entertainment, often far removed from our own day to day lives.

“We decided to create a social media app that is grounded in our community, with all the content shared on the app being relevant to the real lives of its users – and which puts the focus on enabling friendships in the real world.”

Butterfly is only available to users with a Warwick student email, which keeps the content grounded in the realities of campus life. As well as creating their profile pages – the Butterfly ‘Flashcard,’ – and posting thoughts and confessions, users can chat with their course-mates or explore societies and campus events before deciding to attend, taking a bit of the anxiety out of trying something new.

Regular giveaways and prizes keep the community engaged, and there are perks for registered users such as discounts. Alex says “We now have over 60 discounts at partner stores, exclusive to Butterfly users. Our partners now include Kasbah, Tenpin, Phat Buns, Royal Pug, and Boom Battle Bar Coventry.”

“We also have a fantastic partnership with Benugo,” Alex added. “Butterfly users can get 10 per cent off anything on the menu and we ran a competition last year where the app’s most enthusiastic users won a free meal with a plus one. That really captured our ethos of supporting students to grow their real-life friendships.”

Commenting on the app, first year student Sofia said: “Butterfly has completely changed my university experience at Warwick. It has built my confidence and encouraged me to go to loads of events.”

Since its launch in September last year Butterfly has been downloaded 3,000 times. Its creators have won Warwick’s Student Enterprise Competition and been accepted onto Google’s Startups for Cloud Programme.

The app is available in the App StoreLink opens in a new window and Google PlayLink opens in a new window .

People in their midlife are disproportionately more likely to suffer from clinical depression, take their own lives, become dependent on alcohol, have trouble sleeping, and exhibit other extreme-stress ailments.

In the CAGE working paper, ‘The Mid-life Crisis’, Osea Giuntella, Sally McManus, Redzo Mujcic, Andrew J. Oswald, Nattavudh Powdthavee and Ahmed Tohamy use a wide array of population-level health data across all ages to prove that midlife crises are real and affect a high number of people in developed countries.

People in their 40s and 50s in developed countries are typically at their peak earnings and usually have not yet experienced significant illness or disability. Yet, adults in this age bracket report finding it hard to concentrate, say they more likely to forget things, are more likely to suffer from migraines and feel more overwhelmed at work. They are also more likely to suffer depression, develop dependency on alcohol and commit suicide.

The paradoxical association between high living standards and rising dissatisfaction in midlife is yet to be explained. But the findings are a clarion call for policymakers to pay attention to the issue.

The research uses decades’ worth of panel and longitudinal data on health and wellbeing capturing the experience of around 500,000 individuals from developed countries including the UK, USA, France and Australia.

Nine key natural distress indicators were picked from a wide range of surveys including the British household panel survey (BHPS) and the Household Income and Labour Dynamics in Australia (HILDA) survey. These indicators were: suicide, sleeping problems, alcohol dependence, concentration difficulties, memory problems, intense job strain, disabling headaches, suicidal feelings, and extreme depression.

The results drawn from these data sources prove the existence of the midlife crisis. All the markers of distress that were measured followed a consistent trend that peaks between people’s late 40s and early 50s.

Strikingly, the data shows that those in midlife are twice as likely to be depressed than those under the age of 25 or over the age of 65. Suicide rates, the ultimate measure of exceptional distress within a society, were also shown to be the highest among individuals in their early 50’s.

The authors make sense of this by considering the cumulative effect of how smaller issues like poor sleep, headaches and job stress mount up and affect those in middle age over time. For example, panel data from 18,000 Canadians found that migraines peaked in midlife. Migraines were also found to be one of the strongest predictors of extreme depression.

Within-person longitudinal changes in migraines from a sample of over 200,000 people from the BHPS shows a similar trend. The data is controlled for socioeconomic variables including an individual's income and the number of young children they might have. Noticeably, migraines spike at the midlife point, between the ages of 40 and 50.

This peak is found across a fleet of other measures taken by the authors, for example, in reports of alcohol dependence and suicidal thoughts for a one-year period in 2014 from the NHS’s Adult Psychiatric Morbidity Survey (APMS). For the 7,500 recordings taken, the peak observation level is yet again observed at midlife in the 40–50 age bracket. The trend is the same for the other six indicators of distress (suicide, sleeping problems, concentration difficulties, memory problems, intense job strain, and extreme depression) mentioned above.

While no definitive explanation has yet been found to explain the midlife crisis, the authors were able to rule out the effects of income differentials and children.

Intriguingly, the spikes at midlife found in the authors’ data are also found in data relating to our primate relatives, chimpanzees and orang-utans.

Whether midlife crises are caused by societal pressures or are an innate biological phenomenon, the extensive evidence of the midlife crisis across the developed world shows that governments need to start paying attention to what is driving unhappiness in society.

• Giuntella, O., McManus, S., Mujcic, R., Oswald, A.J., Powdthavee, N., and Tohamy, A. (2022). The midlife crisis. CAGE Working Paper (No. 641).

Homes in conservation areas may be responsible for between 3 and 4million tons of avoidable CO2 emissions every year.

 Retrofitting homes can not only improve energy efficiency, but also reduce household bills and lower carbon footprint. Retrofitting can be a complex and costly process for any household. But new research shows that additional restrictions in conservation areas are putting residents off making changes to their homes, changes that could reduce the UK’s CO2 emissions by between 3 and 4 million tonnes every year.

There are over 10,000 conservation areas in England, and every local authority has at least one. Some local authorities, such as Bath, Islington and Westminster, have over 50% of their housing stock in conservation areas.

In most conservation areas, adding photovoltaic installations that are visible from the street, exterior wall insulation or window replacements requires planning permission from the local authority. Professor Thiemo FetzerLink opens in a new window, from the University of Warwick and the CAGE Research CentreLink opens in a new window, has calculated the extent to which these restrictions are deterring homeowners from making their homes more energy efficient.

Analysing data from Energy Performance Certificates and granular actual energy consumption data at postcode level for 239 English local authorities for which data was available, Professor Fetzer calculated the ‘energy efficiency gap’ of homes in conservation areas. He found that the 2 million properties inside conservation areas could save between 17,000 and 21,500 GwH in energy per year and between 3 and 4 million tonnes of CO2 emissions per year if they were retrofitted to the highest standard.

Most homes across the country are not fitted to the highest standard of energy efficiency. But a comparison of retrofitting of homes inside conservation areas with homes of a similar age, size, price, council tax status, and location outside conservation areas shows that homes in conservation areas are falling behind on retrofitting. In fact, this ‘retrofit gap’ (the difference in the amount and quality of retrofitting between homes in conservation areas and similar homes outside conservation areas) accounts for between 5 and 15% of the energy efficiency gap in conservation areas.

As properties outside conservation areas can retrofit at a faster rate (because they do not have to wait for planning departments to approve the works) this retrofit gap is widening.

The research demonstrates the urgent need for policymakers to find ways to make retrofitting easier in conservation areas. Professor Fetzer said,

Through retrofitting residents can play their part in addressing the climate crisis. But the data suggests that restrictions in conservation areas are a significant barrier. Removing or reforming these restrictions is something that all local authorities should look at urgently.

A toolkit developed by Christopher Procter of the Architects Climate Action NetworkLink opens in a new window may provide some concrete input into effective changes that councils across the UK should consider.

Professor Fetzer added:

Conservation areas originated in a period that saw fast changes to the lived environment brought about by growing car ownership in the 1960s. The climate crisis is the direct result of the carbonization of our economies and societies that followed. I hope that in 2023, residents living in conservation areas can reconnect with their original purpose: to limit the rapid environmental change. Back in the 1960s, the environment was changing because of growing car use – now, global heating is a much more fundamental threat to the lived environment. To achieve that, residents in conservation areas need to come together and become advocates for change. In the current regulatory environment, they threaten to fall behind.”

Policy wise, the government could be now very quick to announce a retrofit funding package for conservation areas. But this would be not very wise. Residents in conservation areas are, on average, better off financially than residents outside. So financially, they should not be given an untargeted hand-out to do what needs to be done. Rather, the government and local authorities should be investing in their own skills and capabilities, for example, by working with researchers together to spring to action to help residents in conservation areas to redefine what constitutes the specific character of their area and devise a plan on how to retrofit at scale in a coordinated and cost effective manner.”

• Fetzer, T. (2023) ‘Regulatory barriers to climate action: Evidence from Conservation Areas in England’ can be accessed here http://bit.ly/3jIISli
• The toolkit developed by Christopher Procter, part of the ACAN Architects Climate Action Network Existing Buildings working group can be accessed here: https://www.designingbuildings.co.uk/wiki/ACAN_climate_emergency_conservation_area_toolkit

New research co-authored by Dr Nikhil DattaLink opens in a new window of Warwick Economics, CAGE and the LSE hit the headlines last week with its key finding that leaving the European Union has added an average of £210 to Britain’s household food bills over the two years to the end of 2021 – a cost felt more deeply by lower-income households, which spend a greater share of their income on food than the better-off.

In total, the researchers estimate that Brexit has cost UK consumers £5.8 billion.

The study - Non-tariff barriers and consumer prices: Evidence from BrexitLink opens in a new window - published by the Centre for Economic PerformanceLink opens in a new window at the LSE, finds that food prices have increased by six per cent and calculates that for the poorest households, this results in a Brexit-induced rise in the overall cost of living of 1.1 per cent - 52 per cent more than the 0.7 per cent rise felt in the top 10 per cent of households.

The authors also explain the factors driving the price increases.

Although the 2021 Trade and Cooperation Agreement ensures that trade between the UK and the EU remains tariff-free, so called ‘non-tariff barriers” such as import and expert checks, rules of origin requirements and sanitary and phytosanitary measures for trade in animals and plants all add time and cost to imports and exports.

Between 50 per cent and 88 per cent of these costs have been passed on to consumers.

Commenting on the analysis, Dr Nikhil Datta Link opens in a new windowsaid: “The policy implications are stark: non-tariff barriers are an important impediment to trade that should be a first-order concern, at least on par with tariffs, for policymakers interested in low consumer prices.

“We calculate that Brexit caused a loss of £210 for the average household, or £5.84 billion overall, when looking at its impact on the food market alone. Since poorer households spend a larger fraction of their income on food, they are hit harder.”

Read the full discussion paper here:

Non-tariff barriers and consumer prices: Evidence from BrexitLink opens in a new window.

Read the coverage:-

https://www.theguardian.com/politics/2022/dec/01/brexit-added-nearly-6bn-to-uk-food-bills-in-two-years-research-finds

https://www.independent.co.uk/business/brexit-checks-added-ps210-to-household-food-bills-research-finds-b2236594.html

A new study reveals the growing influence of wealthy individuals in political affairs, particularly in the affairs of the Conservative party. The report also highlights a growing inequality between the financial resources of the two leading parties, which could have significant effects for democracy over the long term.

New research from the CAGE Research CentreLink opens in a new window at the University of Warwick explores political donations to UK parties over the last 20 years. The data reveals that donations have almost trebled over the period, rising from £41 million in 2001 to £101 million in 2019. Individual giving has also risen substantially, with 60% of donations in 2019 coming from private individuals.

The increases in donations have favoured the Conservative party, which had £27 million more in financial resources than Labour in 2019, even when taking account of the public funding received by Labour (known as ‘Short Money’) that is designed to balance resources across the parties.

Key findings:

• Almost half of donations received in 2019 (45.4%) came from private individual ‘super-donors’, who gave at least £100,000 in a single year. In 2017, they made up only 30.8% of total donations.
• The growth in donations from private super-donors is driven by a small group of individuals donating more and more often. In the 2019 election year, 104 super donors gifted £46 million an average of £442,000 each.
• The Conservative party is the main recipient of super-donor gifts. In 2019, they received £21.5 million from 71 private super-donors. The Brexit Party (now ‘Reform UK’) was also notable in receiving the top donation in 2019 – £9.7 million from the businessman Christopher Harborne.
• The 2019 election year saw the biggest surge in donations across the 20-year period, reaching £101 million in real terms. This was an increase of around £37­­ million relative to the level in 2017. In contrast, total donations actually fell by £7 million between the 2015 and 2017 elections.
• This surge disproportionately benefited the Conservative Party, who received £17 million more than in 2015 (+48% change). In contrast, Labour experienced a £6.2 million drop in total donations (-26.7% change).
• Private individuals accounted for 60% of all donations in the 2019 election. This compares to approximately 40% in the early and mid-2000s and 50% during the 2010s up until 2019.

The findings reveal the growing influence of wealthy individuals in political affairs, particularly in the affairs of the Conservative party. They also highlight a growing inequality between the financial resources of the two leading parties, which could have significant effects for democracy over the long term.

Opposition parties are given ‘Short Money’ as financial assistance to rebalance the financial advantage gained from being the sitting government. Historically, this money has been enough to level the playing field. But the surge in donations to the Conservative party over the last 5 years means that this is no longer the case.

Professor Mirko Draca, from the CAGE Research CentreLink opens in a new window and the University of Warwick, said, “We estimate that the resource gap between Conservatives and Labour is over £27 million. This dwarfs any support offered through ‘Short Money’.

“The Conservative finances are so vastly stronger than Labour’s that we could be looking at a prolonged period of financial imbalance between the parties that persists into the next election.”

Professor Colin Green, from the Norwegian University of Science and TechnologyLink opens in a new window, said “This growth in political donations, from a concentration of large individual donors, indicates how unelected private individuals are in a position to wield substantial influence over the UK’s political process.

“Traditionally, UK donations are seen as relatively unimportant when compared to the US. But the significant increase in party donations we see over the last 20 years suggests they are having a very real impact on how the UK democratic process works.”

• Read the paper: Draca, M., Green, C. and Homroy, S. (2022) Financing UK Democracy: A Stocktake of 20 Years of Political Donations Disclosure. CAGE working paper no. 642Link opens in a new window
• Read a blog by co-author Professor Colin Green Financing UK Democracy: Are we heading for a crisis? Link opens in a new window

In the UK, small and medium size firms (SMEs - firms with less than 250 employees) are very important to the economy: they account for three fifths of the employment and around half of turnover in the UK private sector. So, it is not surprising that the UK government has a wide variety of initiatives to support small business growth, from loans to technical advice.

However, one feature of the UK tax system may be actively discouraging the growth of SMEs - the requirement to register for VAT once taxable turnover exceeds the threshold, currently £85,000.

Crossing the threshold usually increases the amount of VAT paid by a firm, and also incurs costs in complying with the rules, such as completing VAT returns. Are these costs sufficiently off-putting that firms deliberately restrict their growth in order to stay below the threshold?

To explore this question Professor Ben Lockwood, Dr Li Liu, senior economist at the International Monetary Fund and Dr Eddy Tam of King’s College London have studied the effect of the threshold on growth using HMRC data on all firms in the UK between 2004-5 and 2014-15.

They find that annual growth in turnover starts to slow when a firm’s turnover gets to within about £20,000 of the threshold and slows by up to 2 percentage points as firms get closer to the threshold - a slowdown of up to 25 percent in the growth rate. There is no evidence of compensating acceleration in growth once a firm crosses the threshold. The research finds similar effects of the threshold on the growth of non-incorporated businesses such as sole traders, partnerships, and unincorporated associations.

To explore this effect further the paper also compares data from firms that are voluntarily registered for VAT (even when their turnover is below the VAT threshold) with firms that are not registered, and finds a sharp difference between these two types of firms as they approach the threshold - voluntary registered firms do not slow down at all, whereas the other firms slow down sharply, with growth falling 3-4 percentage points.

The researchers also look at differences between firms that join the flat rate scheme (FRS), a simplified VAT scheme for small businesses in the UK that is explicitly designed to reduce compliance costs, and those that do not. A firm's VAT liability in the FRS is a single rate of tax times the total turnover of the business. As a result, the FRS is effectively a turnover tax, and only requires businesses to keep track of total turnover rather than a separate record of each purchase and sale, and should be less burdensome than regular VAT. They find that firms that register for VAT via the FRS slow down less before the VAT threshold than those that do not, so the FRS does appear to mitigate the effect of the threshold.

Professor Lockwood comments: “Our analysis finds robust evidence that growth in turnover slows down as firms approach the threshold, with no evidence of higher growth when the threshold is passed. We conclude that by setting the threshold for VAT registration at this relatively high level the government is inadvertently inhibiting the growth of small firms.”

• Read Professor Lockwood’s blogLink opens in a new window, explaining the findings in more detail
• Li Liu, Ben Lockwood and Eddy Tam (2022), Small Firm Growth and the VAT Threshold: Evidence for the UK CAGE working paper No. 631