Measurement Economic Benefits of Education Investment

The concept of the rate of return on investment in education is very similar to that for any other investment. It is a summary of the costs and benefits of the investment incurred at different points in time, and it is expressed in an annual (percentage) yield, similar to that quoted for savings accounts or government bonds.

Returns on investment in education based on human capital theory have been estimated since the late 1950s. Human capital theory puts forward the concept that investments in education increase future productivity. There have been thousands of estimates, from a wide variety of countries; some based on studies done over time and some based on new econometric techniques. All reaffirm the importance of human capital theory.

The rise in earnings inequality, and the subsequent increase in the returns on schooling experienced during the 1980s and 1990s in many countries, led to renewed interest in estimates of returns on educational investment. The literature suggests that systematic changes in the production process brought about by changes in technology and the growth of the knowledge-based economy whereby product cycles become shorter and flexibility is needed, led to changes in the demand for skilled labor.

An Illustration

For illustrative purposes, assume that an eighteen-year-old secondary-school graduate is driven only by monetary considerations in deciding whether or not to invest in a four-year university degree. Such a student will have to contemplate and compare the costs and benefits associated with going to college. The cost per year for tuition and other related expenses ($10,000 in this hypothetical case) is the direct cost. In addition, the student will incur an indirect (or opportunity) cost because he or she will not be able to work while attending college. This cost is approximated by what the average student with a secondary school diploma earns in the labor market, perhaps $20,000 per year. On the benefits side, the student expects to be making, on average, approximately $15,000 more than a secondary school graduate over his or her lifetime after graduating from college.

A rough way to summarize the above costs and benefits is to divide the annual benefit of $15,000 by the lump-sum cost of $120,000, yielding a 12.5 percent rate of return on investment in education. The logic of this calculation is similar to that of buying a $120,000 bond giving an annual coupon of $15,000. The yield of the bond is 12.5 percent.

Private Versus Social Costs

A very important distinction in rate of return calculations is whether one evaluates the private cost or the social cost of an education. The example given above refers to a private rate of return, where the costs are what the individual actually pays in order to receive an education. A social rate of return calculation includes, on the cost side, the full resource cost of one's education. That is, it includes not only what the individual pays, but also what it really costs society to educate one person. In most countries education is heavily subsidized, so the social cost is much higher than the private cost. The social rate of return, therefore, is typically less than the corresponding private rate of return.

Beyond the above monetary calculations used to arrive at a private rate of return, the social rate of return should ideally include the externalities associated with education. This is, of course, extremely difficult to measure, and the issue of externalities has remained a qualification accompanying rate of return estimates–in the sense that such rates, as conventionally computed on the basis of monetary earnings and costs, must underestimate the true social return on investment in education.

The earnings of educated individuals do not reflect the external benefits that affect society as a whole. Such benefits are known as externalities or spillover benefits, since they spill over to other members of the community. They are often hard to identify and even harder to measure. In the case of education, some studies have succeeded in identifying positive externalities, but few have been able to quantify them. If one could include externalities, then social rates of return might well be higher than private rates of return on education.

Empirical Findings

Typically, returns on educational investment are higher at lower levels of schooling and also higher for countries at lower levels of economic development. The scarcity of human capital in low-income countries provides a significant premium to investing in education. The high returns on primary education provide an added justification for making education a priority in developing countries.

In low-income countries, the returns are high, as can be seen in Table 1, which presents an illustrative summary of typical rates of return. Estimates of rates of return over a range of country types show the usual pattern most researchers find. For low-income countries, rates of return can be as high as 12 percent or more. In middle-income countries similar estimates can be found. In many eastern European transition economies, returns are relatively low, but rising. In high-income countries, rates of return on education tend to be lower than in lower-income countries. However, during the 1980s and 1990s returns on schooling increased in these countries, especially in the United States.

Private rates of return are higher than social returns. This is because of the public subsidization of education and the fact that typical social rate of return estimates are not able to include social benefits. Nevertheless, the degree of public subsidization increases with the level of education, which has regressive policy implications. Illustrative rates of return for a variety of countries are shown in Table 2. Higher education remains a profitable investment for individuals in high-income countries, as represented by the private rate of return. There is an even greater private incentive to invest in education in middle- and low-income countries. In these countries the social returns on education are particularly high, signaling a priority investment for society.

Overall, women receive higher returns on their schooling investments, though the returns on primary education are much higher for men (20%) than for women (13%). Women experience higher returns on secondary education (18% versus 14%, respectively).

The highest returns on a per-country basis are recorded for low- and middle-income countries. Overall, the average rate of return on another year of schooling is about 10 percent. From 1990 to 2002, average returns on schooling have declined by 0.6 percent. At the same time, average schooling levels have increased. Therefore (and according to human capital theory), everything else being the same, an increase in the supply of education has led to a slight decrease in the returns on schooling. That is, if there are no "shocks,"–such as changes in technology–that increase the demand for schooling, then an increase in overall school levels should lead to a decrease in the returns of schooling. Over the recent decades the returns to schooling have declined in many low income countries, while the technological revolution has increased demand for skilled labor in developed countries and the returns to schooling have increased.

Estimation Issues

Ideally, a rate of return on investment in education should be based on a representative sample of a country's population. But in reality this is the exception rather than the rule. It is problematic when the estimated rates of return are based on a survey of firms (rather than households), because firm-based samples are highly selective. In order to control survey costs, such samples focus on large firms with many employees. Second, the questionnaire is typically filled out by the payroll department rather than by the individual employee. This approach leads to the use of samples concentrated only in urban areas.

Another problem occurs when rate-of-return estimates are based on samples that include civil servants, since public-sector wages, in most cases, do not reflect market wages. Of course, in many countries (although fewer than in the past) the majority of graduates end up in public-sector employment.

The concentration of graduates in public-sector employment is identified as a problem in major growth studies. However, rate-of-return estimates based on civil-service pay are useful in private calculations regarding the incentives set by the state to invest in education.

A less serious problem occurs when wage effects are confused for returns on investment. Jacob Mincer has provided a great service and convenience in estimating returns on educational investment by means of the well-known earnings function he first put forward that explains differences in earnings among individuals according to their differences in schooling attainments and work experience.

Another methodological limitation is that many researchers feel obliged to include in the regression whatever independent variables they seem to have in the data set, including occupation. In effect, this procedure leads to those other variables taking away a significant part of the effect of education on earnings that comes from occupational mobility.

Perhaps the returns on education estimates that stem from the work of Ashenfelter and colleagues using twins, and other natural experiments, are the most reliable of all. According to this work, the overall private rate of return on investment in education in the United States is of the order of 10 percent, and this figure establishes a benchmark for what the social rate of return would be (a couple of percentage points lower, if not adjusted for externalities), or what the rate of return should be in a country with a lower per capita income than the United States (several percentage points higher, as based on the extrapolation of the noncomparable returns on education presented earlier).

Extensions

More research on the social benefits of schooling is needed. For developing countries, there is a need for more evidence on the impact of education on earnings using a quasi-experimental design–for example, looking at the earnings of different groups, say those exposed to a special training program and those who are not; or children who received early interventions such as nutrition and those who did not. There are more opportunities in the early twenty-first century for this type of research. Moreover, this research needs to be used to create programs that promote investment and reform financing mechanisms.

TABLE 1

There is a concern in the literature with social rates of return that include true social benefits, or externalities. Efforts to make such estimates are numerous, but the estimates vary widely. If one could include externalities, then social rates of return may well be higher than private rates. Richard Venniker's 2000 review found that empirical evidence is scarce and inconclusive, providing some support for human capital externalities (though this support is not very strong and has been disputed). These studies estimate externalities in the form of an individual's human capital enhancing the productivity of other factors of production through channels that are not internalized by the individual (similar to Lucas's 1998 theory). As Venniker states, the evidence is not unambiguous. In fact, some estimates give negative values, while others give very high estimates.

A few studies in Africa have focused on estimating external benefits of education in agriculture using the education of neighboring farmers. A one-year rise in the average primary schooling of neighboring farmers is associated with a 4.3 percent rise in output, compared to a 2.8 percent effect of one's own primary education in Uganda. Another study found that neighboring farmers' education raises productivity by 56 percent, while one's own education raises productivity by only 2 percent in Ethiopia; however, the 56 percent figure seems rather high. Overall, the results are inconclusive.

TABLE 2

Not only has the academic literature on returns on schooling increased, both in quantity and quality, but the policy implications have changed as well. Returns on education are no longer seen as prescriptive, but rather as indicators, suggesting areas of concentration. A good example is the impact of technology on wage differentials, which has led to a huge literature on changing wage structures.

At the same time, the importance of returns on education is seen in their adoption as a key indicator by the Organisation for Economic Co-operation and Development (OECD) in their annual Education ata Glance series and other policy documents. Increasingly, governments and other agencies are funding studies of returns on education, along with other research, to guide macro-policy decisions about the organization and financing of education reforms. This was the case in the United Kingdom higher education reforms as well as the Australian highereducation financing reforms.

Innovative use of rate-of-return studies is being used to both set overall policy guidelines and to evaluate specific programs. Examples include the Indonesia school building program, India's Operation Blackboard project, and Ethiopia's major sector investment program.

Above all, returns on investment in education are a useful indicator of the productivity of education, and they serve as an incentive for individuals to invest in their own human capital. As such, they can play an important role in the design of policies and the crafting of incentives that both promote investment and ensure that low-income families make an investment in education.