Introduction

As the COVID-19 pandemic began to impact Michigan in March of 2020, within the first couple of months, counties across the state reported vastly different rates of COVID-19 incidence and mortality (Schulz et al. 2020). Similar to the rest of the USA, COVID-19 systematically and disproportionately affected communities of color and those from lower socio-economic classes in Michigan (Anderson-Carpenter and Neal 2022; Schulz et al. 2020). In April 2020, data from the state of Michigan showed that 32% of COVID-19 cases and 41% of deaths due to COVID-19 were among Black people, who make up 14% of Michigan’s population (Coronavirus-Michigan Data 2020). Similar racial inequities in mortality were evident during the second and third waves of COVID-19 in Michigan (Zelner et al. 2021). By 2022, although there was a reduction in the racial gap, Black Michiganders, compared to other races, continued to die from COVID-19 at a disproportionate rate relative to their share in the population (Parpia et al. 2021).

Racial disparities in COVID-19 mortality are driven by structural racism in health, housing, labor, and other systems that place Black, Brown, and Indigenous populations at greater risk for COVID-19 exposure, transmission, and severe illness, compared to non-Hispanic White populations (Parpia et al. 2021; Zelner et al. 2021). Race and class hierarchies are intersectional, causing people of color to comprise a disproportionate share of the low-wage “essential workforce,” where risk for COVID-19 infection is highest (The Lancet 2020). Low-income families of color are more likely to reside in smaller living spaces, have larger households, and have family members from multiple generations living under one roof, all of which can influence risk of infection and the rate of COVID-19 transmission (Parpia et al. 2021). Members of low-income households are also more likely to experience food insecurity, rent burdens, and other chronic stressors that contribute to biological weathering and subsequently weakened immune systems, which may result in a higher risk of infection and greater severity of disease (Frontline Communities Hit Hardest by COVID-19 2020; Geronimus et al. 2006). These factors, together with material, psychosocial, and environmental inequities brought on by systemic racism, also contribute to higher rates of chronic health conditions in low-income communities of color generally, and Black communities specifically, such as cardiovascular disease, diabetes, and obesity, all of which can lead to greater severity of COVID-19 once contracted (Gaskin et al. 2014; Gee and Ford 2011; Parpia et al. 2021).

Many of these factors can be connected to the historical and contemporary racist policies and processes, including those responsible for segregation and economic disinvestment, that have systematically harmed Black Americans and benefitted White Americans (Phelan and Link 2015; Tan et al. 2021). For instance, segregation is known to contribute to stark racial inequities in home values and race-related access to well-paying jobs, affordable housing, and adequately funded school systems. As the revenue derived from property values and the costs associated with poverty are critical to local government fiscal health, racialized inequalities in income and wealth may shape local governments’ budgeting decisions, investment priorities, infrastructures, and service levels–producing material differences in public life and population health (Eisenberg 2021; León-Moreta 2019).

However, while research continues to examine COVID-19 disparities at the neighborhood and individual levels, inequalities in the fiscal conditions of local governments have not been explored as structural factors contributing to COVID-19 racial inequities. In Michigan, local public health departments have worked to prevent and control diseases by providing the majority of the COVID-19 response across the state (Michigan's Guide to Public Health for Local Governing Entities 2006). Ultimately, access to resources such as testing, treatment options, and vaccine distribution can be linked to the strength of public health funding and infrastructure at the local and county levels (Dearinger 2020; Michigan Department of Health and Human Services 2020). During the pandemic, local health departments have had the great responsibility of handling emergency response without the necessary resources for adequately doing so after years of chronic underfunding.

Local health departments in Michigan are mandated by the state to provide a broad array of services to protect population health by preventing disease and injury (Citizens Research Council of Michigan 2018). Local health departments struggle to provide these services when state and federal funding do not meet the minimum requirements. While the Michigan legislature requires a 50–50 cost share of public health operations between the state and local health departments, actual state funding is only 30 to 40% with an annual budgetary shortfall of nearly $40 million (Essential Local Public Health Services Funding Committee 2019). In the past few decades, federal and state funding available to local health departments has been sparse, leaving them underfunded and in significant fiscal stress (Eisenberg 2021; Joassart-Marcelli et al. 2005). At $13 per person in 2017, Michigan ranked seventh lowest among U.S. states in terms of state per-capita investment in public health (Citizens Research Council of Michigan 2018).

Michigan local governments rely heavily on local property taxes as a primary source of funding (Michigan Department of Treasury 2018). Decreases in taxable values resulted in reductions in local government property tax revenues, thereby reducing local health departments’ ability to fund and deliver adequate public health services (Kleine and Schulz 2017). After the economic recession of the late 2000s, property values in Michigan dropped sharply by 18.1% and increased only 0.3% as of 2017, despite general economic recovery. This is due in part to a state policy restricting taxable value increases to five percent or the rate of inflation, whichever is less (Kleine and Schulz 2017). In other words, although counties can experience a dramatic drop in property values, these values can only increase slowly due to this constitutional cap, resulting in a deliberately constrained recovery. A Michigan State University report details the connection between low taxable values and inadequate public services, demonstrating that fiscally burdened local health departments lack the capacity and resources necessary to perform essential public health functions (Kleine and Schulz 2017). This may lead to the exacerbation of population health inequities in a cyclical manner, as cities and regions unable to provide adequate services may experience population decline and subsequent reductions in taxable values, thereby further decreasing their revenue and public health funding. Such a cycle would likely have a disparate impact on Black communities, given that prior policies have led Black populations to suffer jointly from structured disadvantage in the housing market and disproportionate burdens of poor health (Fullilove and Wallace 2011).

The purpose of this study is to explore the association between local public health funding measured through taxable property values per capita on county-level COVID-19 death rates in Michigan. Taxable property values per capita is defined by the Michigan Department of Treasury as: “The service-level solvency or the ability of a local government to generate revenues so they can provide public services.” (COUNTIES- Insights Dashboard n.d.). Although not a perfect measure of public health funding, it provides us with some insight on a county’s ability to respond to imminent needs including COVID-19 response, as the higher the taxable property value, the better equipped the local government is to deliver these public services. Therefore, we expect that counties with higher taxable values, and more funding for public health services and resources, will have lower COVID-19 death rates compared to counties with lower taxable values. From this study, we can then begin exploring institutional racism driving some of the COVID-19 racial disparities.

Methods

Study setting

Michigan’s 83 counties are served by 45 local health departments, categorized into city, county, and multi-county districts (Michigan's Guide to Public Health for Local Governing Entities 2006). Each local health department is separate from the state health department and part of the local government. Thirty counties utilize a single-county health department structure, and the remaining 53 counties are part of multi-county health departments. Each of these multi-county health departments, of which there are 14 total, include anywhere from two to ten counties. Detroit is the only city in Michigan with its own health department, distinct from the health departments of the counties in which it resides.

We limited the sample to counties with more than 10,000 residents. Death rates during this period averaged between 1–2% of the population. In 2019, the mean population for the counties included in our sample was 132,429, while the population size ranged from 10,405 to 1,749,343 (U.S. Census Bureau 2019). Supplement 1 includes all of Michigan counties with corresponding taxable values and cumulative death rates.

Study design and sample

This is a cross-sectional study of secondary data from multiple sources, including the Michigan Community Financial Dashboard (COUNTIES - Insights Dashboard n.d.), the COVID Tracking Project (Cumulative Death Rate per 100,000 as of April 30, 2021 [Map] n.d.), the American Community Survey (U.S. Census Bureau 2019), and the Community Health Rankings and Roadmap (County Health Rankings & Roadmaps 2016).

Dependent variable

We used the cumulative COVID-19 death rate for the health outcome, measured as the cumulative death rate per 100,000 population as of April 30, 2021, for each county in Michigan. These data were gathered via Social Explorer from the COVID Tracking Project established by The Atlantic (Cumulative Death Rate per 100,000 as of April 30 2021 [Map] n.d.; The Data: COVID-19 n.d.). The COVID Tracking Project compiles data directly from the websites of state public health authorities. We elected to use COVID-19 death rate as the dependent variable, as opposed to case numbers, since we are less interested in incidence of COVID-19. Several factors contribute to disparities in death rates, and we sought to expand upon this by examining whether taxable values also contributed to disparities in death rates.

Independent variable

Taxable value per capita in 2019 was used as a proxy for fiscal health at the county level and was derived from the Michigan Community Financial Dashboard via the Open Data Network (COUNTIES - Insights Dashboard n.d.). Taxable values are calculated based on the State Equalized Value (SEV) of six groups of real estate (residential, commercial, industrial, developmental, agricultural, and timber cutover), and personal property, MCL 211.34c (The General Property Tax Act 206, Sec. 34c. n.d.). The SEV tends to mirror the property’s assessed value as determined by the local tax assessor, which, according to the MCL 211.27a law, should be equal to 50% of its true cash value. While this measure has been used in urban studies and public finance research, it is not as commonly used in public health literature (Chernick et al. 2017; Hackworth 2018). The variable was treated as continuous and transformed to per 1000 to better interpret the models.

Control variables included population density, age (percentage of population in the county aged 65 years and over), education (percentage of population in the county with a high school diploma or more), race (percentage of population in the county identifying as non-Hispanic White), and income (the county’s median household income). All of these variables were derived from the 2015–2019 American Community Survey 5-year estimates. In addition, we controlled for various health outcomes closely associated with COVID-19, including obesity and diabetes county prevalence, and the percentage of current smokers aged 18 year and older in the county. Data for these variables were obtained from the most recent County Health Rankings and Roadmaps collection year (County Health Rankings & Roadmaps 2016).

Data analysis

Descriptive analysis was used to describe the mean values for each variable used in the study. Two maps were created to depict the geographic distribution of cumulative death rates and taxable values per capita. Quintiles were used to determine distribution. To explore the association between counties’ taxable values and COVID-19 mortality, we regressed county cumulative COVID-19 related death rates on the taxable value per capita for each county, controlling for population density, age, education, race, income, obesity, diabetes, and smoking rates.

Results

A total of 75 counties of a possible 83, were included in the study. As part of our exclusion criteria, eight counties with less than 10,000 residents were excluded. In Table 1, we present descriptive statistics for the full sample, including the mean and standard deviations at the county level.

Table 1 Sample mean and standard deviation for all study variables

Across these counties, the mean population aged 65 years and over was 20.5%. Most counties had residents that were predominantly non-Hispanic White and residents with high school education or more. The mean median income was $52,553.90 and the mean taxable value per capita was $43,764.50, although the range (not shown) was $23,983 to $132,302 in the 75 counties.

Figures 1 and 2 illustrate the geographic distribution of taxable values per person and cumulative death rates, respectively. In Fig. 1, darker shaded areas represented higher taxable values, while in Fig. 2, darker shaded areas represented higher cumulative death rates.

Fig. 1
figure 1

Michigan counties and corresponding taxable values per person with darker shades representing higher taxable values

Fig. 2
figure 2

Michigan counties and corresponding cumulative death rates per 100,000, with darker shades representing higher rates

The state is divided into upper and lower peninsulas. The majority of excluded areas were located within the upper peninsula. Generally, counties with higher taxable values per capita corresponded with lower cumulative death rates with the exception of Gogebic, Iron, Dickinson, and Delta counties in the southwest, and some counties on the east of the lower peninsula, including Presque Isle, Alcona, and Huron counties.

Table 2 presents the county level cumulative COVID-19 related death rates regressed on taxable values per capita while controlling for population density, age, race, high school education, median income, diabetes, obesity, and smoking. Findings from our model show that counties with higher taxable values per capita were associated with lower COVID-19 related death rates (Beta coefficient (B) = –2.45, P < 0.001). Higher population densities (B = 0.06, P < 0.05) and higher proportions of residents over the age of 65 (B = 8.88, P < 0.05) were also associated with higher COVID-19 related death rates among counties in the sample. No issues with multicollinearity were detected in the models (variance inflation factor < 3).

Table 2 County level cumulative COVID-19 related death rates regressed on taxable values per capita

Discussion

Our findings indicated that at the county level, higher taxable values per capita were associated with lower COVID-19 death rates after controlling for various socio-economic and health variables. These findings have implications for future research and policy as discussed below.

Michigan COVID-19 inequities and funding

This study is one of the first to examine county-level taxable value per capita as an indicator of public health funding disparities and its associations with COVID-19 death rates in Michigan. Our findings align with other studies that show lower funding for local health departments is associated with the inadequate provision of public services and leads to poorer health outcomes (Citizens Research Council of Michigan 2018).

Counties across the state have experienced a historical trend of lack of funding, due to reductions in state and federal funding and decreases in taxable values triggered by the economic recession, and therefore likely had underdeveloped infrastructures that contributed to a higher risk of death among residents of those counties infected with COVID-19 (Cafer and Rosenthal 2020). Local public health infrastructure is particularly important for COVID-19 pandemic response. The speed and quality of COVID-19 response across Michigan is largely dependent on the resources and capacity of county and local health departments. For example, testing and vaccine distribution are two mitigation strategies that are influenced by the ability of health departments to efficiently and effectively reach as many people as possible. Counties with historically low taxable values and therefore low levels of funding for public health prior to COVID-19 were subsequently ill-prepared to execute a strong pandemic response. Without a strong response, COVID-19 death disparities were exacerbated with areas that lacked resources being more impacted.

As seen in Fig. 1 (map), the counties with the lowest taxable value per capita were Wayne county and Genesee county. These counties are home to the largest non-Hispanic Black populations, mostly residing in the cities of Detroit (Wayne county) and Flint (Genesee county). These counties also have some of the highest poverty rates in the state and the association between poverty and race can be largely attributed to anti-Black structural racism (Mack 2019). At the individual level, the legacy of redlining practices of the 1930s resulted in restricting access to purchase homes by Black Americans (Rothstein 2018). At the neighborhood level, federal investments in highway funds resulted in the destruction of Black homes, neighborhoods, and businesses, as well as the relocation of employment opportunities and reduced access of non-Hispanic Black individuals to suburban housing (Rothstein 2018). By the 1970s, as members of the cities’ tax bases fled, the cities’ ability to provide public health services and invest in infrastructure continued to weaken (Bosman and Davey 2016). Such moves resulted in the disinvestment of Detroit, Flint, and other majority-Black cities, including the depreciation of housing values (Dewar et al. 2015). Both Flint in 2011 and Detroit in 2013 were placed under state control by appointment of an emergency financial manager, due in part to the aftermath of the 2008 economic recession, including accumulating debt and losses of the affluent tax base (Emergency Manager Law 2016). To study these impacts further, Michigan alone does not provide a sufficient sample with less than 15% of counties having slightly over 10% of non-Hispanic Black residents. However, future studies can aggregate counties from other Mid-western states that have experienced similar processes to better examine these structural determinants of health.

The results from this study should be considered in light of some limitations. The use of taxable value per capita as a proxy for county-level public health does not consider other potential sources of funding available, including emergency funds from the state and federal governments. Funding for public health departments comes from multiple sources and as a direct result of the pandemic, greater financial aid was provided by the federal and state governments. These emergency funds provided temporary assistance that did not address the existing inequities, and although the aid was made available to health departments, underfunded departments lacked the infrastructure necessary to effectively deliver the aid. This study provides insight to the inequitable conditions under which local public health departments functioned prior to the pandemic and how counties with historically larger revenues were better positioned to implement pandemic response and preventive measures compared to their chronically underfunded counterparts. Future studies could explore other avenues of funding and representations of county-level fiscal status.

In addition, we did not control the politicalization of the pandemic during our study period in Michigan. Response to the COVID-19 pandemic has been heavily influenced by politics impacting mandates, including COVID-19 restrictions on mask-wearing and vaccines, with opinions often divided through party lines (NW et al. 2022). The political divide was evident in the 2020 election, with just 50.6% of Michigan residents (11 of 83 Michigan counties) voting for Biden over Trump (Live Election Results 2020). Future studies should more closely examine these factors in association with public health funding and COVID-19 outcomes.

This study has implications for policies moving forward, particularly those concerning local revenue structures and funding for public health services. Restrictive policies, such as Michigan’s state policy that places an annual cap on taxable value increases, negatively impact the long-term financial stability of counties and their ability to provide local public health services (Kleine and Schulz 2017). Additionally, local health departments will continue to struggle to provide services to their communities without the Michigan legislature increasing funding to fulfill its mandate of the 50–50 cost share toward implementation of the Essential Local Public Health Services (Essential Local Public Health Services Funding Committee 2019). Funding provided by the state must also be distributed more equitably by shifting toward a system that more accurately represents the actual costs associated with operating programs, such as the formulas proposed in the 2019 Essential Local Public Health Services Funding Report (Essential Local Public Health Services Funding Committee 2019). Finally, policies should be designed to consider, and repair the historic and current impacts of structural racism. In 2020, Michigan’s Governor, Gretchen Whitmer, created the Michigan Coronavirus Task Force on Racial Disparities to address the historical and systemic inequities across the state. Since its establishment, several initiatives have been implemented addressing food insecurity, housing instability, and employment disparities across the state (MDHHS - Coronavirus Task Force on Racial Disparities n.d.). However, the negative association between taxable value per capita and COVID-19 fatalities in the state of Michigan reveals a need to reevaluate the aforementioned policies, not solely for their inequitable impact on local governments' financial solvency and service quality, but also for their  negative  consequences for population health and racial health equity.