Publication by Virginia Deane Abernethy

by Virginia Abernethy

Ester Boserup’s ground-breaking analysis of the dynamics of agricultural development was one of the highlights of my graduate school reading. I encountered it shortly after its 1965 publication date, in the midst of a controversy at Harvard’s Department of Social Relations [Anthropology] that centered on historical, even accidental v. functional, i.e. causal, explanation of social systems. Boserup’s thesis seemed to confirm the       value of exploring causality.                                                                   

Her focus is on technologies in primitive and developing societies where the more "developed" technologies yield less per man-hour of labor, but more total food because more of the available land is under cultivation. Her analysis is not intended to be relevant where fossil fuel largely replaces human labor, as in the mechanized agriculture of modern societies.

Whether Boserup correctly identified the causal factors in agricultural development is almost a secondary question. Her breakthrough was seeing that particular technologies do not develop, and are not adopted, in a social or environmental vacuum. Local conditions have to be right before agriculturalists will adopt more productive technologies, even if they are perfectly aware and able to adopt them.

Boserup assumes that people resist labor. Therefore, they resist agricultural practices that entail more labor. Necessity drives the invention or adoption of these more labor-intensive technologies. The driver, in Boserup’s view, is the increasing demand for food that comes from population growth.

She takes agriculture from its most primitive stage – gardening that relies on fire to clear forest patches that are cultivated for only a few years and then abandoned. The earth is so friable, fertile, and weed-free in this kind of shifting agriculture that seeds and root-crop eyes can be inserted with a digging stick and left to mature on their own. But maintenance of this quality of soil requires returning a patch to forest after just a few year’s use, and then letting it fallow for 20 or more years. The system works well so long as population density is low enough for forests always to hold virgin or well-regenerated plots.

If population grows so that plot rotation is limited, each clearing must be worked longer, fallow periods are shortened, and gardening becomes more difficult because weeds flourish, fertility declines, and the ground may harden. Plants need to be cultivated. Fertilizer such as fish may be added to enhance soil quality. Hoes replace digging sticks. Labor intensifies.

The next step is from shortened fallow periods to permanently cleared and enlarged plots. The land is now divided into fields and cannot be gardened with a hoe. A primitive plow and draught animals must help, requiring considerable strength and much human labor.

If land is insufficient to provide year-round graze for draught animals, the farmer [shifting agriculturalist and gardener no longer] must also contrive to plant forage and add the chore of feeding livestock. A legume crop may be introduced, both as feed and to restore soil fertility. Irrigation and terracing to maximize land-use may also develop.

Pretty soon the farmer and his family work during all daylight hours, twelve months a year. He is producing much more food than formerly because more of the available land is cultivated, but the trade-off is less leisure. Also, farm families live near neighbors, some also engaged in agriculture but others specializing in crafts. If the household becomes less self-sufficient in its various requirements, enough food – now often grains – must be grown to provide a cash crop. Again, the trade-off is not ideal because the grains laboriously cultivated in plow agriculture yield fewer calories per acre than the root crops grown in long-fallow forest plots.

The transition to intensive agriculture may sound grim. Boserup’s point, indeed, is that the added work requirements are a serious deterrent to making the switch from less to more productive technologies. She suggests that farmers often endure reduction in their food consumption before abandoning the less labor-intensive alternative. Making the point, she presents examples showing that people often revert to the less labor-intensive technology when population pressure eases.

Boserup’s great contribution is drawing attention to causal relationships and motivation. Yet, she unnecessarily in my opinion sets up a Malthusian straw man. Challenging a simplistic version of Malthus’ hypothesis, viz., food supply governs "the rate of population growth" [p.11], she sets out to show that population growth, itself, drives people to increase the production of food. She never acknowledges that perceived scarcity could change demographic outcomes.

Moreover, Boserup’s world knows no environmental limit other than arable land. She would be quite at home with certain economists’ cornucopian views that scarcity is always a short-term phenomenon because higher prices, signaling scarcity, drive both/either substitution and/or enhanced technology. One can accept almost all of Boserup’s conclusions, I think, but this one.

Observation of the world around forces an acknowledgement, in my opinion, that humans inevitably encounter limits in some essential resource, not necessarily land. Therefore, there are limits to what human ingenuity and work can do.

For example, Boserup points out that the transition from long-fallow forest gardening to cleared and plowed fields often dries out the soil. She never, however, looks at the possibility that erosion or climate change including desertification can be induced by human attempts to maximize agricultural production in marginally dry climates. She never examines fresh water as an ultimate limiting resource.

Boserup also gives short shrift to values other than leisure that are given up in the quest to feed a larger and larger population. She makes no mention of the diverse plant and animal species that exist in the forest and its margins but die out when their habitat is destroyed. What, further, of the value that some people place on wilderness, space, mobility, and other intangibles that lose out to crowding and population growth? What of the value that makes settlers move on when neighbors get so close that you can smell their smoke?

I think that the most fundamental criticism is that Boserup limits herself unnecessarily in seeing only one causal direction: population growth driving an increase in agricultural intensification in order to increase food production. A complete picture of population dynamics would include the possibility of a feedback loop. That is, Boserup does not consider that perceived scarcity of food – and much less, that scarcity of some other valued resource – might retard, stop, or even reverse population growth.

The intervening demographic variable that Boserup does not consider is the fertility rate. Leaving aside possible changes in mortality, population growth is mediated by the number of children per woman, largely an effect of desired family size and reproductive behavior. Longitudinal studies show that fertility rates often vary dramatically within a single society and may pulse up or down depending upon perceived economic conditions.

My research suggests that perception of resource availability influences desired family size. Thus, perceived need for more food may drive changes in demographic variables, rather than population pressure simply driving food production. The causal pathway can run in either direction.

The idea that the perception of scarcity depresses fertility rates is not new. Malthus’ Second Essay comes to this conclusion, similar to my explanation now usually called the fertility opportunity hypothesis.

This hypothesis proposes that couples who perceive narrowing opportunity tend to limit family size by whatever means is available. If the sense of scarcity persists, mechanisms that limit reproductive opportunity may evolve beyond individual control to become more or less mandatory patterns of social behavior. For example, in eighteenth century Switzerland and certain German principalities, a general understanding that couples should delay marriage until having a relatively assured financial future evolved into rules that a prospective groom prove an income – such as two years of gainful employment and not having been on the public dole.

On the other hand, people who see expanding opportunity tend to abandon reproductive self-restraint. They are more likely to marry young and welcome new additions to the family. Social or physical mechanisms for limiting fertility are likely to be ignored. Thus, attempts to introduce modern contraception in developing societies are largely unsuccessful so long as people think that the opportunity structure favors large families.

Perception may not be reality. The perception of growing prosperity is what, in my view, propelled rapid population growth in parts of the world where promised redistribution of wealth, or foreign aid, or introduced technologies, or new markets made formerly poor people much better off. Uniformly, these populations raised their fertility rate – or maintained a high rate even as modern medicine was reducing infant and child mortality.

Almost uniformly, however, the apparent prosperity of developing countries [and European countries through the nineteenth century] has been short-lived because rapid population growth quickly reduces per capita income and wealth. The cycles of building optimism, rising fertility rates, and an exploding population followed by disillusionment, rediscovered self-restraint, and declining fertility rates repeat themselves without end.

The choices available to those who see their livelihood disappearing are limited. Barring outside intervention or the possibility of emigration, choices narrow to 1] what Boserup describes and 2] what I describe as the fertility opportunity hypothesis. Both responses are adaptive and, in my experience, often co-exist. People work harder, and people also avoid adding to their responsibilities through marriage and childbearing.

Two illustrations of the hypothesis fall within the spectrum of agricultural societies that interest Boserup. Below are short histories of Malawi and Rwanda presented from the perspective of the fertility opportunity hypothesis.

Malawi is on the Southeast coast of Africa. Its first, 1966, census revealed a population of 4 million. By 1995, the population was 10 million, from which is calculated an annual population growth rate of 3.5%.

Confronted with a rising population and limited arable land, the 85% of Malawians who derive their livelihood from subsistence farming have 3 options for maintaining a viable ecological niche. Ezekiel Kalipeni [1996] concludes that they can 1] work harder on existing holdings, that is, practice agricultural intensification -- the Boserup hypothesis; 2] migrate to available but less good, in fact, marginal lands; or 3] limit family size to avoid adding to existing pressure on the land – the fertility opportunity hypothesis.

Kalipeni suggests that the hard work of agricultural intensification held greatest promise when land scarcity first began to seem problematic but, in the long run, could not keep ahead of the momentum of population growth. Migration to infertile marginal land was unattractive, leaving only the option of limiting family size.

In comparison with other sub-Saharan Africans, rural Malawians began treating fertility control as a real choice relatively early. Between 1977 and 1987, crude birth rates declined from 48 to 41 births per 1000 persons in the population.

Kalipeni tested a number of academic explanations – call them demography’s "received wisdom" -- for declining fertility but found no significant relationships. He found that the fertility rate was not significantly related to education, infant mortality, or urbanization in either 1977 or 1987 data. However, a 1987 regression [correlation] revealed a statistically significant inverse relationship between the fertility rate and population density (r = –0.40). That is, the denser the population, the lower the fertility rate.

Drawing together his data, Kalipeni infers that land hunger was the central stimulus in the onset of Malawi’s fertility decline. He writes: "Correlation does not prove causality. Nevertheless, variation in the rate at which fertility is declining within regions suggests that land hunger does, indeed, drive the more cautious approach to childbearing: specifically, the fastest fertility decline is occurring in the region of highest population density…. areas that are experiencing intense environmental pressure are also beginning to go through a fertility transition" (Kalipeni 1996, p. 299–300).

Rwanda, in Central Africa, is one of the most densely populated countries of the continent. The colonial power, Belgium, and successor indigenous governments (beginning in 1962) recognized growing population pressure but, avers demographer John May, projected an image of expansionary opportunity until the 1980s.

The governments’ principal responses to population pressure after World War II were agricultural intensification and "extensification." Extensification entailed dispersing the Rwandan population to empty paysannats within Rwanda and to less congested territories in neighboring countries (Zaire, now the Democratic Republic of Congo, Uganda, and Tanzania). These strategies, especially relocation, became "by far the most important policy response ever adopted in Rwanda to cope with rapid population growth" (May 1995, p. 329).

May speculates that agricultural extensification created a frontier mentality—an image of opportunity—and that these expansive expectations may have raised the fertility rate: "In fact, the relative availability of land … might have been conducive to higher fertility levels" (May 1995, p. 329).

The mid-1980s fertility rate was 8.5 births per woman. By the 1990s, Rwanda was "the most densely populated country of continental sub-Saharan Africa" (May 1995, p. 333). States demographer Leon Bouvier, "Largely because of extremely high fertility, [the population] quadrupled between 1950 and 1993" (Bouvier 1995, p. 1).

Belatedly in 1981, donors of international aid forced the initiation of a national family planning effort. Fertility began to decline in 1985 and within 5 years arrived at 6.2, a fall of more than 2 children per woman.

One could easily infer that offering women modern contraception caused the fertility decline. That, nevertheless, would overlook a contrary fact: by 1992, only 12.9% of married, reproductive-age women used modern contraceptive methods. Later marriage, May observes, was the most visible contributor to the Rwandan fertility decline (May 1995).

Independent of contraception, any couple can choose to postpone marriage, and any society can develop social or cultural institutions that encourage it. Delayed marriage is just one of many adjustments that can be made in any society—rural or not, deeply illiterate or not, patriarchal or not. Delayed marriage in response to hard times has been observed in many European countries as well as African counties and may be a pan-human response to adversity.

For example, Yoruba villagers in Nigeria explicitly ascribe decisions to delay marriage to "hard economic times" (Caldwell et al. 1992, p. 237). Nineteenth century Irish, well before the 1845 famine, responded to the decreasing size of inherited plots in each generation with very late marriage or celibacy in a very large fraction of the population (Connell 1968). More examples are in Population Politics [Abernethy 1993, [2000]].

John May reasons that Rwandans began to delay marriage by the late 1980s because the incentive structure had changed. Gains from intensifying agriculture had run their course. Land productivity decreased as marginal soils brought into cultivation 20 years earlier steadily deteriorated. Droughts appeared to worsen, and the competition among alternate uses for land (e.g. cultivation, pastureland, forests, and domestic woodlots for fuel) intensified.

Political realities ruled out further population dispersal, so family plots were subdivided to accommodate each maturing generation. Many farms reached a size that barely supports a family. By 1984, 57% of family holdings were less than 1 hectare in size (May 1995).

The shrinking opportunity structure apparently forced itself into Rwandan calculations by the mid-1980s and accounted for delaying marriages and first births. The new availability of modern contraception no doubt helped by making it easier to space and limit births within marriage.

The beginning and course of population cycles are sometimes shrouded in history. One may conclude, nevertheless, that the Malawian and Rwandan stories illustrate the effects of contrasting expectations. Relatively early, the Malawians accepted a theory of limits on arable land. Rwandans farmers, on the contrary, were encouraged to believe that the settlement of fertile new lands would be a continuing option.

Both cases illustrate how societies cast about for the adaptation most suited to their particular circumstances. The Rwandan case, with the preference for moving to empty lands rather than intensifying agriculture locally, strongly supports Boserup’s contentions that the easier, "least work" alternative is usually preferred. Both the Rwandan and Malawian cases also support the fertility opportunity hypothesis – when no better alternative exists, perceptions of scarcity drive reproductive self-restraint. People reduce family size when they see that it enhances future opportunities for a better life.

Boserup provides a model for exploring causality, and she was one of the first to include a demographic variable in a functional analysis of economic development. We will not say that she got it backwards. Rather, her model is one of at least two possible models for explaining how the economy and population are linked. Readers who seek to see how "everything is related to everything else" will find this volume both enjoyable and enlightening.

			REFERENCES