Issues in the estimation and application of latent structure models of choice

Our paper provides a brief review and summary of issues and advances in the use of latent structure and other finite mixture models in the analysis of choice data. Focus is directed to three primary areas: (1) estimation and computational issues, (2) specification and interpretation issues, and (3) future research issues. We comment on what latent structure models have promised, what has been, to date, delivered, and what we should look forward to in the future.     

Saving Accounts versus Stocks and Bonds in Household Portfolio Allocation

We study the structure of household portfolios of financial wealth by analyzing both the determinants of total financial wealth and the choice between risky (stocks and bonds) and riskfree assets (saving accounts). The econometric specification is a generalized trivariate Tobit model, estimated on a cross section of 3,077 households in the Netherlands in 1988. We account for endogeneity of financial wealth and for selectivity due to nonreporting. Results show that the level of financial wealth and the marginal tax rate are major determinants of the allocation between riskfree and risky assets.     

EFFECTS OF THE FARMER SUPPORT PROGRAMME AND CHANGES IN MARKETING POLICIES ON MAIZE PRODUCTION IN SOUTH AFRICA

This article analyses the effects of action aimed at narrowing the gap between South Africa's ‘two agricultures’, specifically the effects of the Farmer Support Programme (FSP) on structural aspects of maize production under different marketing policies. This is done by assembling a sectoral linear programming model of the South African summer-rainfall grain-producing area. The emphasis is on the inclusion of supply, demand and production risk. Results show that the effects of a successful FSP on specific interest groups, e.g. consumers of a specific product, or producers in a specific region, depend on the marketing policy followed, as well as on the effectiveness of the FSP. The analysis accentuates the interrelationships in South African crop production and illustrates how past policies ignored regional comparative advantages, distorted regional development and affected social welfare.     

Vulnerability and industrial hazards in industrializing countries: an integrative approach

The extra vulnerability of industrializing countries to environmental problems and industrial accidents cannot be understood or solved by a ‘normal’ scientific analysis. Aspects of the social and institutional context must be included, through analyses based on post-normal science. The standard two-dimensional classification of PNS is modified to have axes ‘social ‘and institutional vulnerabilities’ and ‘complexity of technological hazards’. The analysis is mainly applied to the case of the relatively rare accidents with catastrophic potential. In these, the deaths per accident in India, Mexico and Brazil are much greater than in the industrialized countries. This discrepancy arises partly from location of such plants near residential communities for marginalized workers and their families. Other socio-political factors are relevant, as the role of these countries in the global production system, the enforcement of safety and planning laws, quality of housing, and lifestyle of residents. Reducing the vulnerability of industrializing countries will therefore require major social policies and a comprehension of the limits of the normal scientific and economic approaches to such problems.     

Infrastructures and Societal Change. A View from the Large Technical Systems Field

Infrastructural and societal changes intertwine in multiple ways. This makes the societal implications of infrastructural projects difficult to assess and anticipate. Yet in present day network societies this task is particularly urgent. This paper first identifies two positions that tend to monopolize and deadlock debates. Next it examines two decades of research in the Large Technical System (LTS) research field for alternative approaches to this issue, before finally suggesting distinguishing between the four increasingly indirect moments of (co-) construction of infrastructures and societies. These may be related causally, but also add their own moments of contingency, agency, and choice.     

Standardization Process of Systems Technologies: Creating a Balance between Competition and Cooperation

Many firms are experimenting with how to standardize new technologies. They may use proprietary technologies for their products and services, and let them compete in the market selection. Alternatively, they can cooperate to jointly set a standard and experiment with combinations of market process and cooperation. If firms let the market decide, they can compete with technologies and need not invest time and effort in hammering out a standard. If they do incur the costs of negotiated standardization, they may enable end users to realize the benefits of standards. A hybrid standardization process combines the advantages of both market selection and negotiated decision making. This paper presents a contingency framework to identify conditions that will affect the preferred standardization process for vendors who introduce new technologies. A major contingency that this paper points to is the systemic nature of technologies in information and communication technology industries. The more systemic the technology is (in a way to be clarified), the less likely that firms will establish a hybrid standardization process. One advantage of decomposing technology systems in smaller components (modules) is that this approach enables firms to combine market selection with negotiated selection of standards.