Gerhard Tintner on Charles Frederick Roos’s Dynamic Economics (1936)

Gerhard Tintner’s review of Charles Frederick Roos’s Dynamic Economics: Theoretical and Statistical Studies of Demand, Production and Prices assesses the promise and limitations of a mathematical economics organized around time. Its central judgment is that Roos’s methods deserve serious attention even where his assumptions and conclusions remain questionable. Tintner welcomes the conjunction of mathematical innovation, economic theory, and statistical investigation, but insists that mathematical convenience cannot substitute for economically justified assumptions. The review proceeds from the disciplinary reception of Roos’s work to demand analysis, then production, profit, expectations, and the trade cycle.

Tintner begins by defending the relevance of mathematics and statistics to economics. Mathematics is a form of logical reasoning applicable to social phenomena; statistics is indispensable to an empirical science concerned with mass phenomena. The neglect of G. C. Evans and his school, particularly among European economists, therefore represents a missed opportunity. Yet responsibility is shared: economists resist unfamiliar methods, while mathematicians insufficiently engage established economic traditions. Tintner separates the importance of the new analytical instruments from the validity of particular results.

The principal departure from traditional economics is Roos’s treatment of time and temporal variation. Tintner acknowledges that the selection of particular problems may appear unsystematic, but considers concrete investigations a legitimate route to theoretical progress:

It is especially the treatment of concrete theoretical or even empirical cases which may push economics a good deal further, and the general theory and methodology can and will be developed later.

This defense frames the review’s qualified sympathy. Tintner identifies statistical studies of gasoline demand, industrial growth and decline, residential building, and free and restrained prices, but confines his detailed discussion to theoretical questions. He particularly praises Roos for grounding statistical analysis in economic theory, contrasting this practice with purely empirical economic investigations. His reservations concern the theoretical framework and the status of its assumptions, rather than the undertaking’s empirical ambition.

Roos’s dynamic approach nevertheless inherits weaknesses from the Marshallian tradition: reliance on partial equilibrium and insufficient attention to its limits. Tintner does not dismiss that tradition. He credits it with advances in limited competition and price discrimination, while finding the practical achievements of the Lausanne school’s general-equilibrium approach comparatively slight. His preferred direction is a combination of partial and general equilibrium, supported by developments in utility theory. Roos’s neglect of utility and indifference curves consequently deprives his analysis of resources for interpreting and constraining economic relationships.

Demand is, for Tintner, the book’s strongest theoretical subject. Income and the prices of related goods were already familiar determinants outside the Marshallian school; the distinctive contribution lies in incorporating past influences. That innovation remains insufficiently specified, however, and is joined to convenient functional forms whose economic justification requires scrutiny:

Every demand curve is linear and every cost curve quadratic.

Tintner accepts such forms as potentially necessary approximations, especially when demand functions involve integrals. His objection is that practical conclusions depend upon the approximation selected and might change substantially under another specification. Roos should make this dependence explicit. Conversely, unrestricted mathematical generality offers little guidance unless functions possess economically meaningful properties:

But would it not have been preferable to consider general functional relationships, restricted, however, by a few properties which we really know or which are at least highly probable?

The proposed alternative is neither unrestricted abstraction nor mechanically precise modeling. Tintner seeks general relationships constrained by defensible economic knowledge, with utility theory helping establish their meaning. His criticism of approximation thus concerns the strength of conclusions drawn from it, not its use as such.

Within these limits, Tintner values Roos’s functional definition of demand elasticity and his probabilistic treatment of demand incentives. The normal law of errors is no less arbitrary than a linear demand curve, but the underlying approach to time lags is ingenious because it supplies theoretical explanation rather than merely statistical description. Joint demand and loss leaders likewise contribute to the analysis of monopolistic phenomena and selling costs; here the assumptions do not appreciably undermine the argument.

The assessment becomes less favorable when Roos moves from particular commodities and costs to production and employment throughout the economy:

But only a careful general equilibrium analysis can give us insight into problems of production and employment in the community as a whole.

Roos rightly demands that production theory incorporate dynamic factors, but his results often return to orthodox conclusions. His treatment of profit introduces expectations, risk, and psychological influences in an original way, with similarities to Keynes’s approach. Yet arbitrary functional choices create misleading precision. Entrepreneurial and consumer expectations depend on the economic system as a whole, so partial-equilibrium analysis cannot adequately explain them.

The same limitation affects production incentives, exchange, and cyclical fluctuations. Tintner welcomes attention to expectations in producers’ goods industries but finds their analysis cursory. Roos’s crude quantity-theory framework neglects production stages and their maladjustments—problems his mathematical treatment of lags might illuminate. The review closes with a strong endorsement of the book’s usefulness, especially for mathematical economists and statisticians. Its lasting promise resides in methods for analyzing temporal dependence; fulfilling that promise requires clearer economic restrictions and a stronger account of systemic interdependence.