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Purpose: In this paper, the author tests five econometric methods for cartel detection suggested in the aforementioned papers on a data set covering the so-called Swedish asphalt cartel, where collusive bidding was detected by the Swedish Competition Authority (SCA) in 2001 and later verified by court in 2003. This paper also elaborates on the econometric specifications suggested by Lundberg (2017) and Bergman et al. (2020). The analysis concentrates on collusive bidding on the same contract. Finally, this paper relates the author’s findings to the analysis by Aaltio et al. (2025), who applied the distributional regression approach suggested by Clark et al. (2025) and the machine learning approach suggested by Huber and Imhof (2019) to the Swedish asphalt cartel.

Design/methodology/approach: The author’s data set contains information on procurements of paving and asphalt works (surfacing works) during the period 1995–2009 and the identities of convicted firms, making it possible to analyze bidding behavior before and after the 2003 court order. The empirical strategy is to first test if the econometric methods suggested by Porter and Zona (1993, 1999) and Bajari and Ye (2003) are able to verify the asphalt cartel, as did the methods suggested by Lundberg (2017) and Bergman et al. (2020). This paper also elaborates on the econometric specifications suggested by Lundberg and Bergman et al.

Findings: In short, when applied to the Swedish asphalt cartel and in contrast to the findings by Porter and Zona (1993) for highway construction contracts on Long Island in the early 1980s, this paper does not find any systematic differences in bidding behavior between competitive and collusive bidders or evidence supporting the hypothesis that the ranking of high cartel bids is related to different determinants than the ranking of competitive or high bids by noncartel firms. Moreover, this paper finds no clear evidence that the probability of submitting bids differs between competitive and cartel bidders, as Porter and Zona (1999) found for school milk procurements by Cincinnati school districts in the 1980s. What this paper do find is a positive correlation between backlog and participation during the cartel period, suggesting that even if the cartel firms are (over)loaded with jobs, they tend to submit bids to create the impression of competition. Besides coordinating their bids, larger cartel members, in terms of the number of bids on different contracts each year, tended to bid less aggressively against each other during the cartel period. The pairwise test of conditional independence by Bajari and Ye (2003) indicates collusive bidding behavior among the convicted firms both during the cartel period and for some of the larger convicted firms after the court order in 2003. One potential explanation for this is that the testing procedure by Bajari and Ye does not discriminate between bids by the designated winner and phony bids by the other cartel members. Adding backlog, the spatial econometric approaches by Lundberg (2017) and Bergman et al. (2020) still verify collusive bidding behavior during the cartel period and reject such behavior for the postcartel period. This result is important as it suggests that the spatial econometric approach is robust to potential omitted variable bias. The result also provides more information to the findings of the bimodal distribution of bids by Aaltio et al. (2025); the phony or predetermined losing bids by members of the cartel are also correlated. That is, leaving a gap to the designated winning bid, the phony bids are not random but coordinated.

Practical implications: From the perspective of a competition authority, some considerations should be made before the authority initiates an investigation into a suspected cartel or conducts a more general scan of several different markets. Firstly, a competition authority often has limited resources and must therefore assess in most cases whether the monetary damage caused by the cartel is substantial enough to justify an investigation and the collection of further information. This should involve the direct economic damage that the cartel inflicts on the contracting authority, but also concern the extent to which the cartel affects the functioning of the market and thereby causes harm to competing companies and consumers. Secondly, are there sufficient procurements to enable an econometric analysis of the companies’ bidding behavior? If not, further analysis must be based on other methods and the collection of additional information to substantiate any suspicions. Thirdly, if there is enough data for an econometric analysis, decide on which econometric method is best suited to detect the suspected behavior or for scanning.

Social implications: Coordinated bids on public contracts are probably more common than this paper realizes. As Harrington (2008) pointed out, …cartels are among us. Their attempts to coordinate the prices they set and the quantities they produce are often effective. […] When we find them, we ought to prosecute and penalize them. But how do we find them? Different econometric methods to detect coordinated bids have been proposed by, among others, Porter and Zona (1993, 1999), Bajari and Ye (2003), Lundberg (2017) and Bergman et al. (2020). But which one should we use? And do they reach the same conclusions? To what extent do they complement each other in our understanding of how the cartel operates?

Originality/value: This paper adds to the existing literature in at least three ways. First, this paper applies and evaluates the different methods on the same data. To our knowledge, this has not been done before with these specific methods. Such evaluation is important for national competition authorities in their choice of econometric method to detect and test for suspicious bid-rigging. Second, by introducing backlog in the econometric specifications used by Lundberg (2017) and Bergman et al. (2020), this paper tests the sensitivity and robustness of their results. Third, this paper complements recent and ongoing research on the evaluation of different econometric methods in this area (Huber and Imhof, 2019; Aaltio et al., 2025). It is possible to obtain a bimodal distribution without the nonwinning cartel bids correlating with each other. It may also be the case that the participating companies rotate in different procurements, which does not create a correlation between the nonwinning bidders (as they do not participate in many procurements due to this rotation), while still achieving a bimodal distribution of the cartel’s bids.

A key challenge in cartel enforcement is identifying collusive agreements. We study two major Nordic procurement cartels that operated in the asphalt paving market. We find evidence that during the cartel period bids were clustered and the winning bid was isolated. We implement two cartel detection methods that exploit variation in the distribution of bids. The method developed by Clark et al. (forthcoming) correctly rejects competitive bidding for the cartel period in both markets. The method suggested by Huber and Imhof (2019) achieves a high prediction rate in one of the markets but not in the market where the cartel had a more modest impact on bid distribution. Our results suggest that statistical screening methods with low data requirements can be useful for competition authorities in detecting collusive agreements.

Det krävs en bred och oberoende analys av experter med olika kompetens. Låt den oberoende forskningen vid svenska lärosäten vara med och bidra med kunskap i syfte att öka sannolikheten för att den har typen av investeringar i framtiden ska bli lyckade ur ett klimat, samhällsekonomiskt, demokratiskt och socialt hållbart perspektiv

The three closely related COVID-19 outcomes of incidence, intensive care (IC) admission and death, are commonly modelled separately leading to biased estimation of the parameters and relatively poor forecasts. This paper presents a joint spatiotemporal model of the three outcomes based on weekly data that is used for risk prediction and identification of hotspots. The paper applies a pure spatiotemporal model consisting of structured and unstructured spatial and temporal effects and their interaction capturing the effects of the unobserved covariates. The pure spatiotemporal model limits the data requirements to the three outcomes and the population at risk per spatiotemporal unit. The empirical study for the 21 Swedish regions for the period 1 January 2020–4 May 2021 confirms that the joint model predictions outperform the separate model predictions. The fifteen-week-ahead spatiotemporal forecasts (5 May–11 August 2021) show a significant decline in the relative risk of COVID-19 incidence, IC admission, death and number of hotspots.

This research note contains an update of the research program “A promised land? Drivers, challenges and opportunities related to the (green) industrialization of Northern Sweden,” (nr. M22-0029) awarded by the Swedish Riksbankens Jubileumsfond’s in 2022. The document summarizes work in progress and is updated annually in different versions according to the requirements of the program. 

This interdisciplinary program aims to understand the economic, social, and political challenges and opportunities of the ongoing industrial transformation in northern Sweden. A key element of the program is to identify drivers, obstacles, and preconditions in a historical, present, and forward-looking process-perspective. 

Recent large investments in northern Sweden connected to the green transition – primarily within mining and manufacturing (fossil-free steel, batteries) – have led to substantial increases in local demand for labour. In a territory with low unemployment and a decreasing labour supply due to ageing and a history of net outmigration, there is a substantial risk that this increased labour demand will, particularly in the short term, draw at least to some extent from the public sector.

Against this backdrop, the chapter examines the dynamic effects of employment expansion in the mining and manufacturing industries on public sector employment in northern Sweden during the period 1990–2019. It also analyses which factors affect the probability of a worker leaving the public sector for a job in manufacturing or mining.

Our results suggest that the expansion of manufacturing and, in particular, mining has a negative short-term effect on public sector employment. The largest effect is attributable to poaching from public administration, with education and health less affected. Assuming a linear trend based on previous labour market interdependencies, a three standard deviation increase in mining (about 2,700 new jobs) and manufacturing (about 10,800 new jobs) could potentially lead to 8% of the current public administration workforce being poached. The results also indicate that younger individuals, low- and high-income earners, and those highly educated in the social or technical sciences are the most likely to leave the public sector. In the longer perspective, these vacancies go on to be filled by skilled but inexperienced workers.

A number of policy implications arise from the above findings. First, given the regional dimension of job mobility, policy-makers should consider how large investments influence the other parts of a regional economy, rather than simply attending to the immediate demands of focal industries. Second, while the poaching of public sector employees will inevitably occur, the functioning of the public sector also hinges on the supply of workers entering the labour market. There is therefore a pressing need to bolster the status of key public sector jobs and improve working conditions, thereby ensuring they are regarded as viable career opportunities when mining and manufacturing expands. The public sector should also ensure that it is in a position to attract and retain workers crowded out of the mining and manufacturing in the event of future rationalisation. Third, general policy interventions may not serve local needs, especially the spatial mismatch of available jobs and supply of workers. Support for relocation tailored to local demands is therefore crucial.

This paper studies the effect of Green Public Procurement (GPP) on competition, bids, and winning bids under two different regulation periods where the latter include more explicitly expressed GPP ambitions. Based on detailed data from Swedish internal cleaning service procurements, our results imply that environmental considerations might not influence the bids as required for GPP to be considered an effective environmental policy instrument. Over time, lower degree of competition and increased bids are found. This phenomenon can be attributed, at least in part, to regulatory influences, signifying an escalating complexity in the process of submitting bids.

In recent years, Skellefteå has had significant population growth linked to the establishment of Northvolt. Between 2020 and 2023, the population growth in Skellefteå was 4.6 percent, which should be compared with an average population growth of 1.7 percent in Sweden. The main purpose of the report has been to describe how the labor market in Skellefteå has changed after 2017. 

The population growth can largely be explained by a sharp increase in immigration. For many years, the municipality has indeed had a positive net migration which, however, has not been able to compensate for the aging population. Therefore, the population has remained at stable levels until 2017. The strong immigration in recent years is mainly made up of men aged 25 to 64. In general, the proportion of men in the age range 15 to 64 is increasing, while the number of women aged 15 to 24 is decreasing, which may pose a future challenge connected to how to break the negative nativity trend. Even before 2017, Skellefteå had a high proportion of men, and the reduction in the number of women aged 15 to 24 may in the long run lead to a further distortion of the gender balance. A large part of the immigrants has for a long time consisted of people from the immediate area (mainly Umeå, but also smaller municipalities). This trend continues after 2017, when the number of migrants from Umeå increased even further. A significant part of the immigrants are also primarily men, but also women, from other countries. This too can pose a future challenge if they are not integrated into society.

Those who move to Skellefteå often get jobs that only require shorter training or introduction. This has increased since the establishment of Northvolt regardless of education level. At the same time, the degree of job changes is high among these immigrants, which indicates that these occupations are entry-level occupations. We also see that emigration has also increased in recent years, and this mainly concerns women aged 15–24. While immigrants mainly come from the surrounding municipalities, young Skellefteå residents move to university towns and the larger cities. In addition to the migration patterns, the commuting patterns have also changed somewhat over time. Commuters to Skellefteå mainly come from Umeå, and this has increased after 2017, followed by Stockholm (which, however, is less than half the number compared to those from Umeå) closely followed by Piteå, Luleå, Norsjö and Robertsfors. Apart from Umeå and to some extent Luleå, the number of individuals for all municipalities to commute from has decreased after 2017, while commuting from Skellefteå also has generally increased. Here too, Umeå is the most common place of work, followed by the neighboring municipalities.

The proportion of employees in professions that require a longer university or college education is increasing in Skellefteå, which in itself is a positive development as it generally reduces sensitivity to future structural changes. On the other hand, the percentage who get a job immediately after graduation is decreasing, even among those with a longer university or college education. This applies both to those already living in Skellefteå, but above all to immigrants who, to an increasingly lesser extent, start working in professions that require a university degree. This may be due to a matching problem between the applicants and the employers. But it may also be due to a change in search behavior among job seekers, where new graduates immediately after graduation first apply for a simpler profession and then for more qualified professions. It may also be due to higher requirements for work experience among employers. As the large majority of immigrants with university qualifications remain within this occupational group, it indicates a growing matching problem driven by over-education as the labour market segments experiencing employment growth do not require university education.

A high school diploma (gymnasium) is the most common highest level of education in Skellefteå. At the same time, the number of employees in professions that require a shorter education or introduction is decreasing. The fact that the number of people employed decreases in professions that require a shorter education or introduction need not be a negative thing given that it does not lead to increased unemployment. It can even be a positive development if it leads to more people being employed with more advanced tasks. On the other hand, it can lead to increased unemployment among individuals with a shorter education, a group that has more difficulty adapting to changed conditions on the labor market. Given such a development, it may become necessary to carry out continuing education efforts for that group. A certain increase in the workforce that has not completed upper secondary education can be seen in recent years and is also a trend that should be actively countered.

Incomes in Skellefteå have risen since 2017, especially men's incomes. Immigrants to Skellefteå generally have lower wages compared to the population as a whole. This is probably due to the fact that the immigrants work to a greater extent in occupations that require shorter training or introduction. The move-in together with generally higher wages and limited construction has had a positive effect on housing prices. Higher housing prices should lead to increased construction in the municipality, but this can be dampened by a higher cost situation (wages, building materials, interest, etc.) in the construction sector. Limited housing construction leads to a redistribution of income from wage earners to property owners. Those who move into Skellefteå live to a greater extent in tenements and condominiums compared to the average Skellefteå resident. Immigrants settle to a large extent in the central parts of Skellefteå. Again, this does not have to be negative as it often takes time for a new mover to get to know a new city and it can take time to find longer-term accommodation. Given that the moving surplus also consists of many young men, centrally located apartments are more suitable for this group compared to detached houses for families with children. The limited mobility on the housing market can be another reason why immigrants end up in certain areas and in certain types of housing to a large extent. It is possible to make some comparisons with the labor market, where a simpler job can be an entry-level job while you are looking for a longer-term job. 

This document lays out the background for the research program “A promised land? Drivers, challenges and opportunities related to the (green) industrialization of Northern Sweden,” (nr. M22-0029) awarded by the Swedish Riksbankens Jubileumsfond’s in 2022. The document summarizes work in progress and may therefore be updated and republished in different versions according to the requirements of the program. 

This interdisciplinary program aims to understand the economic, social, and political challenges and opportunities of the ongoing industrial transformation in northern Sweden. A key element of the program is to identify drivers, obstacles, and preconditions in a historical, present, and forward-looking process-perspective.