The idea that the economy can be fluctuating even if markets are at equilibrium was built into early macro-dynamic models. This is apparent in the models developed by Tinbergen (1934), Kalecki (1935) or Samuelson (1939a,b), where at any point of time the whole production is sold; instead, the movement of the economy stems from the existence of various delays responsible for keeping the economy away from its stationary state. Erik Lundberg pointed to another direction when he published his Studies in the Theory of Economic Expansion (1937). The question he asked was: How would the economy behave when pushed outside of its market equilibrium? At a time when this approach was still exploratory in economic models, his was a groundbreaking study.
With that aim in mind, Lundberg examined the conditions for which an economy may grow steadily and then wondered what would happen if these conditions were not fulfilled. His first step was to show on the basis of a small model (Lundberg, 1937: 185, reproduced hereafter) that the development of investment and capital was necessarily exponential, and that a linear development would lead to imbalances in the economy. Consider a model where a fraction of income is saved at every moment. Assume that is equal to 0.2, and that production is equal to 100 units. Then, if 80 units are consumed, for the equilibrium to be obtained, 20 units need to be invested. Suppose now that there is a fixed relationship between investment and the variations of production such that with for instance . Assuming no depreciation of the stock of capital, we have . With the condition that at each point in time, we obtain the differential equation which represents the model economy, and the solution , where is a constant determined by the initial conditions of the economy. With the values and , this means that the economy will grow at a rate of , a “dynamic equilibrium.”
But Lundberg questioned the possibility of this continued expansion: “Production, consumption, income, savings, and investments are all increasing at certain rates, and we ask whether this growth can continue in some sort of dynamic equilibrium, or whether discrepancies must automatically come into being within the system itself, which have the tendency to interrupt the process” (Lundberg, 1937: 183). For him, the problem comes from the assumed equality between investment and savings: “This equilibrium condition must be disrupted, in order to explain or analyse a development.” Investment must be explained “causally” and not simply assumed to be at its necessary level to offset savings, and this led Lundberg to suggest that “If due regard is paid to the determining factors of investment, the tentative straight-line solution might give a more accurate picture of the system’s inherent tendencies toward discrepancies than the equilibrium solution giving exponential curves” (Lundberg, 1937: 186).
What happens now if the economy is off this balanced trajectory? What happens for instance if what is produced is not sold? Is the economy likely to get back on its initial track? Shall we instead expect to see the disequilibria growing over time? Here are the questions raised by Lundberg and the meaning of the various “sequences” he attempted to build in his book. Lacking the mathematical skills of his fellow economists from the Econometric society, Lundberg fell short of producing alternative mathematical models. However, in pointing in a new direction giving a central role to market disequilibria, he undoubtedly influenced the future direction of research which paid more and more attention to those issues from the 1940s onward.
Kalecki, M. 1935. “A Macrodynamic Theory of Business Cycles.” Econometrica 3(3):327–44. https://www.jstor.org/stable/1905325
Lundberg, Erik. 1937. “Studies on the theory of economic expansion.” Stockholm: Kungl. Boktryckeriet. P. A. Norstedt & Söner
Samuelson, Paul A. 1939a. “A Synthesis of the Principle of Acceleration and the Multiplier.” Journal of Political Economy 47(6):786–97. https://www.jstor.org/stable/1824312
Samuelson, Paul A. 1939b. “Interactions between the Multiplier Analysis and the Principle of Acceleration.” The Review of Economics and Statistics 21(2):75–78. https://www.jstor.org/stable/1927758
Tinbergen, Jan. 1934. “Der Einfluß Der Kaufkraftregulierung Auf Den Konjunkturverlauf.” Zeitschrift Für Nationalökonomie / Journal of Economics 5(3):289–319. https://www.jstor.org/stable/41792889
Wazo kwamba uchumi unaweza kuwa fluctuating hata kama masoko ni katika usawa ilikuwa kujengwa katika mapema macro-dynamic mifano. Hii inaonekana katika mifano iliyoundwa na Tinbergen (1934), Kalecki (1935) au Samuelson (1939a), ambapo wakati wowote uzalishaji wote huuzwa, badala yake, harakati ya uchumi hutokana na kuwepo kwa ucheleweshaji mbalimbali unaohusika na kuifanya uchumi mbali na hali yake ya kusimamishwa. "Erik Lundberg aliandika kitabu chake cha ""Studies in the Theory of Economic Expansion"" mwaka 1937." Swali alilouliza lilikuwa: Uchumi ungefanyaje ukipelekwa nje ya usawa wake wa soko? Wakati ambapo mbinu hii ilikuwa bado ya uchunguzi katika mifano ya kiuchumi, utafiti wake ulikuwa wa kuvutia. Kwa lengo hilo, Lundberg alichunguza hali ambazo uchumi unaweza kukua kwa kasi na kisha akajiuliza nini kingeweza kutokea ikiwa hali hizi hazingetimizwa. Hatua yake ya kwanza ilikuwa kuonyesha, kwa msingi wa mfano mdogo (Lundberg, 1937: 185), kwamba maendeleo ya uwekezaji na mtaji ni lazima exponential, na kwamba maendeleo linear kusababisha imbalance katika uchumi. Fikiria mfano ambapo sehemu ndogo ya mapato huhifadhiwa kila wakati. Kwa mfano, kama tunafanya kazi kwa 0.2 na 0.2, tunapaswa kuwa na uwezo wa kuzalisha bidhaa za 100 kwa siku. Kwa mfano, ikiwa ununuzi wa vitu 80 ni sawa na kiwango cha usawa, basi ununuzi wa vitu 20 ni sawa na kiwango cha usawa. Kwa mfano, kama kuna uhusiano wa kudumu kati ya uwekezaji na mabadiliko ya uzalishaji, kwa mfano, Kwa kudhani hakuna depreciation ya hisa ya mtaji, tuna. Kwa hali kwamba katika kila hatua katika wakati, sisi kupata differential equation ambayo inawakilisha uchumi mfano, na ufumbuzi, ambapo ni mara kwa mara kuamua na hali ya awali ya uchumi. "Lundberg alisisitiza uwezekano wa kuendeleza upanuzi huu: ""Uzalishaji, matumizi, mapato, akiba, na uwekezaji wote wanaongezeka kwa viwango fulani, na tunauliza ikiwa ukuaji huu unaweza kuendelea katika aina fulani ya usawa wa nguvu, au ikiwa tofauti lazima ziwe ndani ya mfumo wenyewe, ambazo zina mwelekeo wa kuvuruga mchakato.""" "Kwa maoni yake, tatizo linatokana na usawa wa uwekezaji na akiba: ""Hii hali ya usawa lazima kuvurugwa, ili kuelezea au kuchambua maendeleo."" ""Uwekezaji lazima kuelezwa ""causally"" na si tu kudhani kuwa katika ngazi yake muhimu ya kusawazisha akiba,"" na hii imesababisha Lundberg kupendekeza kwamba ""Ikiwa kuzingatia kwa usahihi kuamua ya sababu za uwekezaji, tentative line linear ufumbuzi inaweza kutoa picha sahihi zaidi ya mfumo asili mwelekeo kuelekea tofauti kuliko ufumbuzi usawa kutoa.""" Nini kinatokea sasa ikiwa uchumi hauko katika mwendo huu wa usawa? Kwa mfano, ni nini hutokea ikiwa kile kinachozalishwa hakinauzwa? Je, inawezekana kwamba uchumi utarudi kwenye mwendo wake wa awali? Je, badala yake tunapaswa kutarajia kuona ukosefu wa usawa ukiongezeka kwa muda? Hapa ni maswali yaliyoinuliwa na Lundberg na maana ya "mfuatano" mbalimbali alijaribu kujenga katika kitabu chake. Kutokuwa na ujuzi wa hisabati wa wenzake wa uchumi kutoka jamii ya Econometric, Lundberg alishindwa kuzalisha mifano mbadala ya hisabati. Hata hivyo, kwa kuelekeza katika mwelekeo mpya kutoa jukumu kuu kwa usawa wa soko, bila shaka aliathiri mwelekeo wa baadaye wa utafiti ambao ulitoa tahadhari zaidi na zaidi kwa masuala hayo kuanzia miaka ya 1940 na kuendelea. Kalecki, M. 1935 "A Macrodynamic Theory of Business Cycles"" (A Macrodynamic Theory of Business Cycles) ni kitabu cha kwanza cha masomo ya uchumi cha Marekani, kilichochapishwa mwaka wa 1934 na kinachapishwa mwaka wa 1945 na kuchapishwa mwaka wa 1964." "Kama ilivyoelezwa katika ukurasa wa ""Sehemu ya"" (Sehemu ya 1) na ""Sehemu ya"" (Sehemu ya 2) na ""Sehemu ya"" (Sehemu ya 3) na ""Sehemu ya"" (Sehemu ya 3) na ""Sehemu ya"" (Sehemu ya 3) na ""Sehemu ya"" (Sehemu ya 3) na ""Sehemu ya"" (Sehemu ya 3)." Mwaka 1937 <unk>Mafunzo juu ya nadharia ya upanuzi wa kiuchumi.<unk> Stockholm: Kungl. Boktryckeriet. P. A. Norstedt & Söner Samuelson, Paul A. 1939 - Maonyesho ya Ujumbe "A Synthesis of the Principle of Acceleration and the Multiplier"" (Jarida la Uchumi wa Siasa, 476: 786-97)" "Kama ilivyoelezwa katika makala ya ""Status of the World"" ya mwaka 2018 ya JSTOR, ""Status of the World"" ni taarifa ya mwaka 2018 ya JSTOR, iliyochapishwa na Samuel Samuelson, Paul A. Samuelson, na John H. Samuelson." 1939 - Vita vya pili vya dunia "Mtazamo wa ""Multiplier Analysis"" na ""The Principle of Acceleration"" katika The Review of Economics and Statistics, 21 (2): 75-78" "Kama ilivyoelezwa katika makala ya ""Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun.Jun." "Kama ilivyoelezwa katika makala ya ""Kufsaidika kwa uchumi"" ya jarida la ""Zeitschrift für Wirtschaftswissenschaften"" (ZWT) la mwaka wa 2008 na ""Kufsaidika kwa uchumi"" ya mwaka wa 2009." "Hii ni kwa sababu ya ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm"" na ""J-Storm."""