Affordable Housing: An Economic Perspective
Introduction
The challenge of providing affordable housing is a pressing social and economic issue faced by nations across the globe. In his paper, Affordable Housing: An Economic Perspective, economist John F. McDonald brings a rigorous, market-oriented lens to this problem. Rather than viewing it solely through a social justice or architectural framework, McDonald argues that the affordable housing problem must be understood through two interconnected economic tools: consistent measurement and cost-benefit analysis. This article summarizes his key arguments, from the definition of housing affordability to the evaluation of policies like rent control, public housing, and housing vouchers.
The Economist’s Two-Part Framework
McDonald begins by establishing that economists approach social problems differently than planners or activists. The first part of their method is consistent measurement defining the problem in quantifiable terms. The second is the cost-benefit test, which assesses whether a policy’s benefits outweigh its costs, including the option of doing nothing. This framework, he notes, is neither liberal nor conservative per se, but it leads to conclusions that often challenge popular interventions.
A foundational belief among economists (both liberal and conservative) is that housing is most efficiently supplied by a competitive housing market with clearly defined and enforced property rights. In such a market, the best targeted solution for low-income households is a housing voucher program a rent subsidy that allows poor families to choose their own housing in the private market. McDonald is careful to note that poverty alleviation is the ultimate long-term solution, but in the meantime, housing vouchers are the most efficient tool.
However, he raises a critical question often ignored by Western economists: what if a nation lacks well-defined property rights or an effective housing market? In such cases, the voucher model fails. Yet, McDonald insists that even in these challenging environments, consistent measurement and cost-benefit analysis remain essential. Without them, policy becomes guesswork.
Defining and Measuring the Affordable Housing Problem
One of the paper’s most valuable contributions is its breakdown of how to measure affordable housing in practice. McDonald acknowledges that economists are traditionally wary of the term “affordability” because it jumbles together housing prices, housing quality, income distribution, borrowing ability, public policies, and consumer choice. As Quigley and Raphael note, it’s a messy concept. Green and Malpezzi add that any affordability calculation is inherently arbitrary, based on normative judgments about what households “should” pay.
Nevertheless, McDonald outlines five steps required for meaningful measurement:
Setting a standard for low income – This can be absolute (e.g., U.S. poverty line) or relative (e.g., below 30% of median household income). Studies often use 0–30% of median income as the low-income threshold.
Measuring the number of low-income households – Requires consistent periodic surveys. A key complication is that economists prefer “permanent income” (average income over several years) over current income, because housing decisions are long-term. A temporary income dip can make a household appear cost-burdened when it is not.
Defining a minimally acceptable housing unit – This is complex because local building codes vary and are sometimes influenced by special interests. McDonald uses U.S. Department of Housing and Urban Development (HUD) standards: severely inadequate units lack flush toilets, hot water, electricity, or have severe structural flaws; moderately inadequate units have frequent toilet breakdowns, unvented heaters, or multiple upkeep problems. Remarkably, as of 2011, only 3.1% of U.S. rental units were severely inadequate.
Measuring the cost of an acceptable unit – HUD sets “fair market rent” at the 40th percentile of local rent distributions, varying by unit size and location.
Setting the income percentage standard – In the U.S., the benchmark is 30% of household income spent on rent; a “severe” problem is over 50%.
Using these metrics, McDonald presents striking data from the 2011 American Housing Survey. Of 38.9 million renter households, 11.8 million (30.3%) were in the lowest income group (0–30% of median income). Among these, a staggering 7.5 million (64%) paid more than 50% of their income on rent. If the 30% standard is used, 78.1% of the lowest income group had a rent burden. In contrast, only about 0.5 million of these households lived in severely inadequate units. The message is clear: the affordable housing problem in the U.S. is primarily a problem of rent burden, not of dilapidated housing. It is a problem of poverty, not construction quality.
Analysis of Affordable Housing Data and Policies
McDonald distinguishes two types of analysis: studies that track changes in affordability (e.g., why rents rose or incomes fell) and policy impact studies. The latter can be social experiments (rare and expensive) or structural economic models. The most famous social experiments were the Housing Allowance Experiments of the 1970s, which found that offering vouchers to all eligible households had minimal impact on market rents, and that most subsidy value went to non-housing consumption.
Structural models, using empirically estimated elasticities (e.g., income elasticity of housing demand at 0.4, price elasticity at -0.3), allow comparison of different policies. Mayo’s 1986 study is a classic example, comparing public housing, construction subsidies, rent subsidies for new construction, and housing vouchers. The consistent finding: public housing is inferior to housing vouchers in delivering benefits per dollar spent. Public housing suffers from production inefficiency (poor locations, bad design, high labor and administrative costs, lack of market discipline) and restricts consumer choice. Vouchers, by contrast, allow households to buy housing in the competitive market, revealing their true preferences.
A Survey of Affordable Housing Policies
McDonald systematically evaluates the major policy tools used globally.
Rent Control
Rent control comes in three forms: tenancy control (initial rent free, then capped increases), maximum rent systems (fixed nominal rent that erodes with inflation), and split systems (controls only for low-income households). Most economists are highly critical of traditional rent control. It discourages new construction, reduces maintenance, lowers mobility (tenants stay too long), and encourages black markets. While some economists like Arnott advocate for “newer” forms that exempt new construction and allow inflation adjustments, McDonald concludes that most economists take a dim view of rent control as it actually exists.
Public Housing
The U.K.’s Council Housing and the U.S. federal public housing program are examined. The U.K. program, started in 1919, once dominated the rental market, but critics note it impeded mobility. The U.S. program, begun in 1937, produced notorious high-rise “projects” that concentrated poverty, were poorly designed and managed, and have largely been demolished.
McDonald notes that low-rise public housing can be more successful, but the fundamental problem remains: demand far exceeds supply, and public housing is inefficient. Even the modern Low Income Housing Tax Credit (LIHTC) program, which creates mixed-income developments, is likely even less efficient than standard public housing. One study found that a dollar of tax credit raised tenant welfare by only 53 cents, compared to 96 cents for a housing voucher.
Loosening Restrictions on Housing Supply
A consistent finding in housing economics is that local restrictions on supply such as growth moratoriums, urban growth boundaries, large-lot zoning, and fiscal zoning, drive up housing prices and rents. Malpezzi and Green showed that metro areas that restrict new construction have higher rents at the bottom of the quality spectrum. McDonald argues that loosening these restrictions is a powerful pro-affordability policy. However, local governments have fiscal incentives to restrict housing (e.g., favoring commercial tax base), so state or national action is needed to prohibit the worst forms of exclusionary zoning.
Housing Vouchers
Vouchers are the preferred policy of most economists. Introduced in the U.S. in 1974, they have become the primary affordable housing program. A household pays 30% of its income, and HUD pays the landlord the difference up to fair market rent. The advantages are clear: consumer choice, market discipline, and lower cost per unit of benefit. Critics like Bennett, Smith, and Wright argue that vouchers depend on annual congressional appropriations and can be cut, whereas public housing units physically remain. McDonald counters that both programs face funding constraints, but vouchers are simply more efficient. The evidence is persuasive that vouchers produce the same benefit at lower cost or greater benefit at the same cost.
Informal Housing
In developing countries, informal housing (e.g., favelas in Brazil) is the default outcome. Annez and Wheaton’s study of 24 countries found that official housing production records accounted for as little as 14% of actual stock changes in the Philippines. Formal housing quality improves with economic growth (GNP per household), but only if the nation does not impose restrictive supply regulations.
Conclusion: Poverty, Vouchers, and the Long Run
McDonald concludes with several key takeaways. First, the affordable housing problem can be measured, and even in a wealthy nation like the U.S., it is large. Second, the problem is fundamentally one of poverty, not a shortage of physically adequate housing. Alleviating poverty is a very long-run project, but in the meantime, well-designed programs are justified.
Housing vouchers are the most efficient policy, provided the housing market is competitive and property rights are clear. If the private market’s supply response is insufficient, the value of vouchers can be increased. Policymakers should also aggressively loosen restrictions on housing supply at the local level, as these restrictions harm the poor the most. For nations without functional property rights or markets, the first step is institutional change but measurement and cost-benefit analysis should still guide the way.
Finally, McDonald calls for more cost-benefit studies of affordable housing policies and for a measurement system that is directly linked to policy evaluation. Without that link, we cannot know if we are helping or harming the very households we intend to serve. The economist’s perspective is not cold-hearted; it is realistic. If we want to make housing truly affordable, we must follow the evidence even when it challenges long-held political or professional beliefs.
Also Read: Dangiwa Harps On Innovative Housing Finance To Tackle Africa’s Affordability Crisis