高水平均衡陷阱 马克·埃尔文（伊懋可）

The High-level Equilibrium Trap Mark Elvin treats the problem of economic stagnation in the traditional Chinese rural economy as resulting from obstacles to technological innovation. In application to agriculture, Elvin's formulation may be put in these terms: why did the Chinese economy not succeed in introducing technological innovations into the process of cultivation, thereby increasing the productivity of agriculture? Elvin does not maintain that Chinese technology stood still during the medieval period.1 But he does hold that technical advances just managed to keep pace with population increase and resource depletion, with the result that welfare (per capita income) remained fixed (Elvin 1975:87).2 Technical breakthrough did not occur in spite of extensive commercial development, extensive production for the market, and considerable levels of scientific knowledge. Elvin proposes to explain the persistence of technical stagnation in the late traditional economy in terms of his notion of a high-level equilibrium trap. The following passage is formulated in terms of handicraft cotton production, but is equally applicable to farm technology. Why at some point did the economy not generate a demand for cloth that was rising fast enough to smash through the institutional and structural barriers to invention? . . . The Chinese economy as a whole was caught in what may be called a high-level equilibrium trap: a situation to which most of the usual criteria of “backwardness” do not apply, yet characterized by a technological immobility that makes any sustained qualitative economic progress impossible. (Elvin 1972:170) In its simplest form, Elvin describes the trap in these terms: technology had developed to the fullest extent possible (in agriculture and water transport, for example) without a discontinuous jump involving application of modern scientific inputs (Elvin 1973:305-6, 312). The hypothesis that only inputs created by a fairly advanced stage of an industrial-scientific revolution . . . could have saved her agriculture from sharply diminishing returns to new methods, new 1 Elvin describes several important technological advances: the windmill, incubation box, cocoon drying techniques, hothouses, cellars for cotton spinning, new fertilizers and food plants, new navigational techniques, and spectacles. 2 Note that this conforms to Perkins' estimates as well. 2 investment, extra inputs and new use of resources, thus seems more plausible. (Elvin 1973:309)3 Thus Elvin's account has at its core a view about the prerequisites of technical innovation; he explains the failure of economic revolution in China as the consequence of the absence of the necessary preconditions of technical innovation. Elvin summarizes his explanation of technical stagnation under one broad framework--the high-level equilibrium trap. But in fact his analysis identifies a number of separate factors, some of which are interrelated and others independent: · population pressure on resources, particularly land; · an oversupply of cheap labor, favoring labor-intensive innovations; · market efficiency and market size; · the organization of the unit of production (farm, business, cottage industry) and the incentives which this organization presents to various participants; · a lack of available innovations which are both economically and technically feasible. In the following I will briefly survey the main arguments concerning each of these factors and then consider whether the high-level equilibrium trap is one trap or many; does Elvin's formulation and application of the concept change with context? And we will consider whether the HLET is a valid or useful analytical concept for economic history. Does it identify a specific economic circumstance, or is it rather a metaphorical concept which can be loosely fitted to a wide variety of different circumstances? Limits to the refinement of practice Elvin holds that most elements of the HLET model in application to agriculture may be illustrated in terms of a functional relationship between labor and output indicating the efficiency of the production process (figure 1). At any given time in the development of an agricultural system the process of cultivation may be characterized in terms of the techniques available (forms of fertilizer, techniques for processing the soil, implements for cultivating and harvesting, techniques of crop storage, etc.); the forms of organization 3 See also Dwight Perkins' argument to much the same conclusion. 3 and labor use in use; and the forms of labor skill available. The options available in each of these categories constitute the universe of possible forms of cultivation in those historical circumstances; and different cultivators can select different mixes of techniques, skills, and organizational forms through which to cultivate their crops. S TET D E1 E2 E3 E4 P1 P2 P3 P4 I Labor Output O Figure 1. The high-level equilibrium trap In his analysis of figure 1 Elvin makes several simplifying assumptions: most importantly, he assumes that the total cultivated land area is fixed and that the types of techniques available for cultivation are fixed and unchanging. There is a hidden dynamic assumption which should be identified as well: that population will tend to increase to the point that existing agricultural techniques and practices will just satisfy subsistence needs. On these assumptions, farming efficiency can only be affected by choosing more efficient mixes of available techniques over less efficient. Elvin refers to alternative mixes of available techniques as a “practice.” Figure 1 represents output as a function of labor inputs for a given set of techniques of production. Each curve Pi represents a different practice, or mix of inputs per acre (labor, capital, fertilizer; Elvin 1972:171), and the curve plots output for a given level of labor input. Curve OT represents the potential output feasible for the optimal mix of all factors; it is the ideal limit of the given technology. The shape of each curve represents the workings of diminishing marginal returns in agriculture: given that land is fixed, adding one worker to the production process increases the aggregate output, but less and less the more labor is already invested in the process. 4 The line OS represents the level of output needed to satisfy the subsistence needs of a given quantity of labor (population). The break-even point for any given curve Pi is reached when the curve crosses line OS (the subsistence level); no more labor can be absorbed into the process of cultivation and still produce enough grain to satisfy the subsistence needs of all cultivators. Thus the points of intersection Ei represent population equilibrium points; no further population growth can be absorbed within the existing agricultural practice. (Let us refer to these points as “zero-surplus equilibrium points.”) And the distance between a given curve and line OS represents the surplus produced using a given mix of techniques and quantity of labor. The significance of the movement from P1 to P2, then, is that the latter curve represents a more efficient mix of traditional techniques (practice); for a given input of labor the output of grain is greater than for the same labor using practice P1. We may thus look at the progression from P1 to P2, P3, etc., as a historical progression through which cultivators “fine- tune” the resources and techniques available to them.4 Each refinement produces a greater aggregate output for a given level of input, and is capable of supporting a larger population of cultivators. There is a limit, however, to the extent to which refinements of practice can increase efficiency and support a growing population: the curve OT. “When the point ET is reached is this escape route barred: increased inputs of labor, capital, and organization yield no returns. Pre-modern technology and practice are both at a maximum” (Elvin 1972:172). On this account ET is the high-level equilibrium trap. It is a point of equilibrium in that it represents the circumstances in which the largest population can be supported at the subsistence level consistent with a given set of agricultural techniques. Elvin has postulated tendencies towards fine-tuning agricultural practices and increasing population; ET is the point at which this process comes to a rest. If population increases further, some people fall below subsistence levels and the population decreases. Second, ET is a high-level point in that it represents the most efficient possible use of existing agricultural techniques, leading to the largest possible output capable of satisfying subsistence needs of the population. 4 "The constant managerial decisions needed for fine technical tuning were thus in the hands of those closest to the process of production and most directly motivated to take them effectively" (Elvin 1982:14). 5 In what sense, though, is ET a trap? It is a trap in one obvious but weak sense: there are no further modifications of practice which are possible which would further increase productivity.5 But the term “trap” (and Elvin's own usage in other contexts) implies more than this; it suggests that there is a set of obstacles specific to the circumstances of the HLET which will prevent technical development and which would not have blocked technical change at an earlier point in the development. But the model has taken as a premise the fixity of techniques; therefore by construction it is impossible for the model to explain why technical change should be blocked. Being at ET does not prevent technical change any more than any of the Ei do, however. All ET represents is the point at which no further gains can be derived from improving the “mix” of existing technologies. This analysis suggests that the arguments supporting figure 1 must be narrowly limited to this conclusion: If a system arrives at ET (a point of local maximum for available technology), then it will be incapable of escaping from ET without an exogenous shock. But there is nothing inherent in these arguments which should lead us to the conclusion that a traditional society will in fact arrive at ET; it is equally possible that there will be a continuing incremental improvement in technical as well as practical resources. It may be that this limitation is consistent with Elvin's intentions. He may merely intend to assert that traditional China had in fact arrived at a condition perilously close to PT, and not to assert that there was a necessary underlying logic of development which led him to that condition. But if so, the explanatory power of the analysis is greatly reduced. Thus this formulation does not explain technical stagnation, but rather presupposes it; a priori, one might suppose that technical innovation (in the form of a new seed stock, a more efficient plough, or an inexpensive and efficient irrigation pump) is an exogenous variable which may occur at any time. Inventions of these sorts would have the effect of shifting curve OT upward and generating a whole new series of intermediate curves as cultivators experiment with the mix of the newly available techniques. And one might hold that this sort of innovation is equally likely throughout the series of Ei. 5 It might be more accurate to call this a "dead-end" or "cul-de-sac." 6 The “no-surplus” trap In order to interpret ET as a trap we must make a further observation: technical innovation generally requires capital investment (new implements, new water management projects, etc.), and capital investment requires a surplus product in the hands of a cultivator who has an incentive to make these investments. The cost of technical innovation, moreover, extends beyond the cost of the new technology itself to the social costs of the educational, scientific, and technical establishment. If an agrarian system reaches ET, however, there is no surplus available to fund research and investments. Through an extended process of fine-tuning of practices leading to an optimal mix of traditional techniques, and through the tendency for population to increase, there has emerged a system in which cultivation just barely manages to satisfy subsistence needs of the whole population. Finally, for reasons described above, there is no cost-free escape from this condition (no new arrangement of existing techniques which could allow for the creation of a capital fund). This circumstance implies that it will be impossible for the system to finance technical innovation.6 We may summarize this version of the HLET in these terms: 1 Rising population and progressive refinement of traditional techniques leads to an economy in which there is no surplus available to fund technical research and capital investment. It should be evident that this aspect of the argument has a highly malthusian character. This argument depends crucially upon the assumption 6 N. C. R. Crafts offers an account of English economic development that appears to presuppose much the same mechanism: "A number of features of the economy aided fixed capital formation. It has been argued that population growth was restrained by a number of 'preventive checks' on fertility (e.g. delayed marriage), which prevented population size from reaching the maximum consistent with subsistence and thus allowed a surplus to exist which might be used for investment in industry. The surplus, moreover, was distributed very unequally, as it is in most economies. . . . Beginning much earlier but becoming evident in the eighteenth century were new financial institutions, such as the country banks or mercantile credit from foreign trade or the new government debt, which expedited the channelling of the surplus into capital formation" (Crafts 1981:4). 7 of population increase to the level of marginal subsistence.7 As the system approaches this point, the social surplus diminishes to zero and the system is incapable of rescuing itself from its condition of low per capita income. If we modify this assumption about population growth, however, then the conclusion does not follow that the system described has entered an equilibrium effectively blocking the emergence of new and more efficient techniques of production. There are several points at which the “no-surplus” trap is vulnerable. First, it might be argued that population increase will stop before it reaches the point of marginal subsistence. In this case there is a potential surplus available for investment. And in fact, as Kang Chao points out, it is virtually impossible for a population to reach ET, since it would require perfectly equal distribution of the available product in order to support the whole population at the bare subsistence level (Chao 1986:6-7). This latter assumption, however, “can be achieved only with the help of a redistributive mechanism so powerful as to be an impossibility in any society” (Chao 1986:7). Chao argues that the relevant point is rather point F (figure 2), the point at which the marginal contribution of labor is equal to the subsistence wage. If this argument is correct, however, then we should predict, against Elvin, that population increase will stabilize at a point at which a surplus still exists over and above the minimal subsistence needs of the population. 7 "There were several reasons why such an equilibrium became established in China between the fourteenth and the eighteenth centuries. The most important of these was the growing pressure of population on arable land. This meant that the surplus product available for generating demand above the level of subsistence was progressively reduced" (1972:170). 8 Figure 2. The Chao model Source: Chao: 1986:7 This point brings in its train a second: we might accept the point that per capita incomes are driven to a low level but reject the conclusion that the social surplus disappears, by reintroducing class and surplus extraction: landlords push peasants to even lower incomes and acquire a surplus product through rent. This would block Elvin's conclusion of a stationary trap, since it would provide a source of possible capital investment funds. The no-surplus trap presupposes a very low level of stratification in the rural economy: the vast majority population is involved in small-scale cultivation or handicrafts, and income on each unit of production is driven to the level of bare subsistence. This is an unreasonable assumption, however; there persisted significant stratification of land and wealth throughout Chinese rural history. These inequalities rested upon a system of surplus extraction through rent, usury, and taxation; the surplus-extraction system permitted landlords, moneylenders, and the state to confiscate most of the rural surplus for their own use. Victor Lippit shows (1978, 1987) that it is plausible to conclude that roughly 30% of the rural product was available as potential surplus within the traditional economy; and surplus-extraction institutions successfully made this surplus available to the state and a small class of relatively affluent landowners, merchants, and officials. If this 9 account is approximately correct, then the obstacle to technical innovation is not the absolute absence of investment funds; so we need to ask what prevented persons who controlled the available surplus from investing it in rural development. And this question, in turn, suggests that we consider a surplus-extraction model for understanding local class relations and incentives. Finally, we might question the assumption that technical innovations are always costly, demanding high levels of surplus to be discovered and incorporated. Without this assumption, ET is not an inescapable equilibrium point either.8 The “self-exploitation” trap There is a way of treating the previous two points which brings them together: the processes described as “fine-tuning” of traditional practice lead naturally to a large population and a low wage rate; this encourages the emergence of labor-intensive techniques; and given the low wage, capital- intensive techniques cannot compete. Given, though, that technical innovation is typically labor-replacing and capital-intensive, the demographic process means that technical innovations will not be able to compete with traditional techniques. Call this the “cheap labor” trap.9 This point is particularly relevant in virtue of the organization of traditional Chinese agriculture around small family units. For a distinctive feature of peasant agriculture in contrast to capitalist agriculture is its relation to labor power.10 The supply of labor power in a peasant household was largely a given factor at any one time. This is of course the basic difference between the textbook peasant and the textbook capitalist entrepreneur, who varies inputs of both capital and labor as profitability dictates. For a peasant, the fundamental economic decisions revolved around the question of how to make the best use of the labor available to his family. (Elvin 1982:29) 8 Huang gives a series of such examples. 9 As we will see below, Huang criticizes this argument on the ground that there were possible technical innovations which were not labor-replacing but merely enhanced the contribution of each worker. 10 This point was extensively developed under the framework of "self-ex- ploitation" by Chayanov. 10 Along the lines of this